Dias v Petropulos and Another (22639/2009) [2018] ZAWCHC 93; [2018] 4 All SA 153 (WCC); 2018 (6) SA 149 (WCC) (30 July 2018)

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[2018] ZAWCHC 93
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Dias v Petropulos and Another (22639/2009) [2018] ZAWCHC 93; [2018] 4 All SA 153 (WCC); 2018 (6) SA 149 (WCC) (30 July 2018)

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THE
REPUBLIC OF SOUTH AFRICA
IN THE HIGH COURT
OF SOUTH AFRICA
(WESTERN
CAPE DIVISION, CAPE TOWN)
Case
No:  22639/2009
Before
the Hon. Mr Justice Bozalek
Hearing:
21 – 24, 28 – 30 November 2016; 1 December 2016; 27 –
28 February 2017; 1, 8, 13 – 16, 20, 22 March
2017; 24 –
26 April 2017; 2 – 3, 8 – 11 May 2017; 12 – 14; 19
June 2017
Delivered:
30 July 2018
In
the matter between:
ARTUR
FERNANDO PERREIRA DIAS

Plaintiff
and
MARINA
PETROPULOS

1
st
Defendant
DAWID
PETRUS VENTER

2
nd
Defendant
and
NIK
MOROFF & ASSOCIATES
CC

1
st
Third Party
NAUMANN
CONSTRUCTION

2
nd
Third Party
MARINA
PETROPULOS

3
rd
Third Party
DAWID
PETRUS
VENTER

4
th
Third Party
ARTUR
FERNANDO PERREIRA
DIAS

5
th
Third Party
PETER
BERNARD
BABROW

6
th
Third Party
JUDGMENT
BOZALEK
J
[1]
Commencing
in October 2009, the plaintiff, in his capacity as the owner of a
residential dwelling situated at [...] T. A., Camps
Bay, instituted a
damages action against his neighbours, the first and second
defendants, for damage caused to his property. I
shall also refer to
the plaintiff’s property as ‘
the
Dias property’
.
The plaintiff’s case was that the damage to his property was
caused by the mobilisation in June 2008 of the scree mountain
slope
on which it was located. That slope mobilisation, the plaintiff’s
case proceeded, was caused through breaches by the
defendants of the
duty of lateral support they owed to the Dias property. The first
defendant, Mrs Marina Petropulos, is the owner
of one of the
neighbouring properties, namely, [...] B. R., Camps Bay. I shall also
refer to that property, which prior to 2008
was an unimproved erf, as
‘
the
Naumann property’
which is the surname of her husband. Mr Naumann is a builder and was
responsible for all excavation work and building on the Naumann

property which played a critical role in this matter. I shall also
refer to the property which was at all material times owned
by the
second defendant, Mr Dawid Venter, as ‘
the
Venter property’
.
[2]
Thereafter
at the instance of either the first or second defendant or at the
instance of a third party, six third parties were joined.
The first
of them, Nik Moroff and Associates CC (‘
Moroff’
),
is a professional structural engineering practice which was joined in
the action by the first defendant. She alleged that Moroff
(or its
predecessor) was appointed as the project engineer for the works on
the Naumann property and that it was negligent in carrying
out its
mandate. Moroff pleaded to the plaintiff’s particulars of claim
and first defendant’s third party notice and
participated fully
in the trial, disputing the merits of the plaintiff’s claim.
[3]
The
plaintiff’s claim was also opposed by the first and second
defendants. At an early stage in the trial, however, the second

defendant withdrew therefrom after having apparently reached a
settlement agreement with the plaintiff. I shall return to this
issue
later.
The
cases made by the respective parties
[4]
The
mobilisation of the slope, which is at the heart of this matter and
which occurred around July 2008, affected five neighbouring
erven on
the steeply sloping mountainside of Camps Bay. These properties
formed a parcel of land bound between Theresa Avenue,
on the upper
part of the mountainside and Barbara Road on the lower mountain side.
Apart from the Dias, Naumann and Venter properties,
other affected
properties were the Babrow property and the Stylemark property. The
Babrow property is also located on Theresa Avenue
on the upper part
of the mountainside. The Stylemark property borders on the Venter
property on the Sea Point side which in turn
borders on the Naumann
property. All of these last three properties abut onto Barbara
Avenue. Only the Babrow, Naumann and the
Venter properties border on
the Dias property. The Naumann property lies directly below the Dias
property as does, but to a lesser
extent, the Venter property.
[5]
In
the months preceding June 2008, excavations took place on both the
Venter and Naumann properties. In the case of the Naumann
property,
these were preparatory to the building of a residential dwelling on
what had previously been an undeveloped erf. In the
case of the
Venter property, the excavation preceded the building of a new
garage.
[6]
The
core of the plaintiff’s case was pleaded in paragraphs 6 –
8 of its Particulars of Claim as follows:
‘
6.
In carrying out the aforementioned excavation of the First
Defendant’s property,
the First Defendant deprived the
plaintiff’s property of the lateral support to which the
Plaintiff is entitled.
7.
In carrying out the aforementioned excavation on the Second
Defendant’s
property, the Second Defendant deprived the
plaintiff’s property of the lateral support to which the
Plaintiff is entitled.
8.
In consequence thereof and in or about June 2008, the scree slope on
which the
Plaintiff’s property and residence is situated and
constructed, mobilised and subsided through the mechanism of :-
8.1.
a shallow slip circle with uplift at the toe, resulting in vertical
upward bulging of the ground
surface between Barbara Road and the
structures facing onto it; and
8.2.
lateral movement towards Barbara Road.’
[7]
Paragraph
9 read as follows:
‘
The
aforesaid mobilisation of the slope and subsidence caused extensive
damage to the residence and other improvements on the plaintiff’s

property, more particularly in that: -
9.1.
It resulted in the block retaining wall along the boundary of the
property being
undermined and caused it to collapse;
9.2.
It caused lateral movement and subsidence of the garden area up to
the Western façade
of the main house;
9.3.
It caused the swimming pool to settle and translate laterally and to
become detached
from the main house, with the result that the
swimming pool is unusable and requires demolition and rebuilding;
9.4.
It caused damage to the main house in the form of cracking and
movement of walls
and tiles, cracking of floor slabs, movement of
door and window openings and cracking of driveway and boundary
retaining wall on
Theresa Avenue;
9.5.
It caused the entire ground area of plaintiff’s property to
subside, which
subsidence is continuing with continuing structural
damages aforesaid.’
[8]
In
paragraph 10, the plaintiff avers that the mobilisation of the slope
and the subsidence and the damage to his property were caused:
‘
10.1
jointly by the excavation on the first and second defendants’
property;
10.2
alternatively, partially by the excavation on the first defendant’s

property and partially by the excavation on the second defendant’s
property’
In
the further alternative it was averred that these consequences were
caused by the excavation on the first defendant’s property
or
the second defendant’s property alone.
[9]
The
first defendant pleaded that it owed the plaintiff no duty of lateral
support for one or more of the following reasons: firstly,
the
plaintiff’s property was previously excavated, developed and
built up and was no longer in its natural state; secondly,
the
stability of the plaintiff’s property and the land on which it
was situated was compromised by its development or that
of
neighbouring properties. In the alternative, the first defendant
pleaded that in the excavation or the development of its property
it
did not deprive the plaintiff’s property of any lateral support
to which it was entitled. In the further alternative,
i.e. in the
event of it being found that its excavation deprived the plaintiff’s
property of lateral support to which it
was entitled, the defendant
denied that it incurred any liability by the virtue of the
plaintiff’s following conduct:
1.
the
plaintiff consented to the first defendant’s excavation and
thereby waived any right of lateral support it might otherwise
have
had;
2.
the
plaintiff thereby consented to the risk of harm resulting from the
first defendant’s excavation;
3.
any
damage sustained was:
3.1.
not
caused by the result of any breach of legal duty or wrongful conduct
on the part of the first defendant;
3.2.
was
not foreseeable or was too remote to attract liability;
3.3.
was
caused due to the failure on the part of the plaintiff to properly or
duly mitigate his damages.
[10]
The
second defendant similarly denied liability for any damages suffered
by the plaintiff and pleaded that the slope mobilisation
was caused
exclusively by the excavation effected by the first defendant on her
property.
The
separation of issues
[11]
The
first defendant brought an application in terms of Rule 33(4) for
certain issues to be separated out and heard first. The terms
of the
separation were contested by the plaintiff. On 13 May 2016, Saldanha
J made an order in the following terms:
‘
1.
There shall be a separation of issues
in terms of Rule 33(4) in terms of which the following issues,

namely, those arising from paras 1 – 8 of the plaintiff’s
particulars of claim be determined in initio:
a)
Whether
a common law duty to provide lateral support to plaintiff’s
property was owed by each of the first and second defendants

properties;
b)
Whether
excavations carried out on each of the defendant’s properties
in or about May or June 2008 breached this duty of lateral
support;
c)
If
so, whether as a result of the plaintiff’s property being so
deprived of such lateral support by the excavations on one
or both of
the defendant’s properties, the scree slope on which
plaintiff’s property and residence were situated and

constructed mobilised and subsided in or about June 2008.
The further
proceedings in relation to all the remaining issues in the principal
action, the first defendant’s counterclaim
and all the third
parties proceedings are stayed and shall stand over for later
determination.
2.
Notwithstanding that the issues arising inter alia from paragraphs 9
of the plaintiff’s
particulars of claim have been ordered to
stand over for later determination and shall not be determined at the
initial hearing,
this shall not preclude the leading of evidence at
the initial hearing regarding the features of damage to plaintiff’s
and
any other properties which is relevant to the determination of
any issues in (a), (b) or (c).
3.
The cost of the application stand over for determination by the trial
court.’
The
course of the litigation
[12]
Over
a period of some six and a half years the parties exchanged
pleadings, including a claim in reconvention by the first defendant,

brought joinder applications as well as other interlocutory
applications, and sought and furnished extensive trial particulars.

In the result, the pleadings alone ran to 586 pages. Further delays
in the pre-trial procedure meant that the trial on the separated

issues only commenced in November 2016. It too was plagued by delays
and a postponement but ultimately ran for a total of 27 days

excluding argument.
Background
[13]
As
mentioned, prior to 2008 four of the five affected properties had
been developed by excavation and the erection of residential

dwellings, the exception being the Naumann property which was in its
natural state. The Dias property was purchased as a vacant
erf by the
plaintiff in July 1991. The Dias’ appointed architects,
engineers and a building contractor and their residence
was built in
1993. It is a sizeable dwelling although certainly not out of keeping
with neighbouring dwellings.  A swimming
pool is attached to the
house on the seaside.
[14]
A
certain amount of fill from the plaintiff’s excavation was used
to level out the garden facing the sea, i.e. above the Naumann

property. Following complaints from Mr Naumann in 1993 that the
material from their property was falling onto his property (i.e.
the
first defendant’s), the Dias’ commissioned their engineer
to design a retaining wall to solve this problem. A so-called

Loffelstein wall was built on the boundary between the two properties
and no further complaints were forthcoming from Mr Naumann.
[15]
The
Venter and Stylemark properties were already built prior to the Dias
property being constructed. The Venter property was apparently

constructed during the 1980’s.
[16]
In
2007/2008, Mrs Petropolus and Mr Naumann commenced with plans to
build a residential dwelling on the Naumann property. Various

agreements were signed with their neighbours who were apprised of the
nature and scope of the intended construction. The plan involved

excavating the property to produce three tiers each to be retained by
a retaining wall. There would be a bottom/ground level, a
middle
level and a top level standing just below the Dias’ Loffelstein
wall. The plans for the Naumann property also involved
an excavation
for a lift shaft. Excavations on the Naumann property commenced in
March 2008 and were completed within a month or
so. Thereafter
construction of the concrete retaining walls was commenced and
eventually completed some months later. The building
contractor was
Mr Naumann, himself a master builder, using where necessary
contractors. During the course of the construction of
the top
retaining wall the Dias’ Loffelstein retaining wall largely
collapsed.
[17]
At
around the same time as Mr Naumann was effecting his excavation and
the commencement of his building operations, the second defendant
(Mr
Venter) proceeded with an excavation on his property preparatory to
the erection of a new garage. His excavation and newly
constructed
garage were completed but during June/July 2008 subsidence and
cracking problems began to present themselves on his
property. By 23
July 2008 these had reached such proportions that the second
defendant had to evacuate his property, never to return.
In the
meantime similar problems had begun to manifest on the Dias property.
Furrows appeared in the garden between the Dias dwelling
and the
Naumann property and a pool rail pulled away from the house
structure. Alarmed, Mrs Dias contacted Mr Naumann who visited
the
Dias property for an inspection in late July. A geo-technical
engineer, Mr Van Wieringen
(‘Van
Wieringen’
)
was contacted and in due course was jointly appointed by Mr Naumann,
the Dias’ and Mr Venter. A joint meeting of all the
concerned
parties was held in the Dias home on 1 August 2008. Immediately
thereafter Mr Naumann began to implement measures recommended
by Van
Wieringen to stabilise the slope of the mountainside comprising, at
the least, the Dias, Naumann and Venter properties.
By this stage it
had become apparent that the slope was mobilising. To this end Mr
Naumann had plastic sheeting placed over the
garden of the Dias
property to prevent the ingress of the rain water. He also had a
contractor load a considerable amount of fill
back onto the Naumann
and Venter properties. In the ensuing weeks, a specialist contractor,
Fairbrother, grouted many of the cracks
which had appeared in the
Dias garden and pool using a concrete mix. A specialist surveyor, Ms
Valentia Papanicolaou, was appointed
to monitor ground movements on
the respective properties. She set up targets and commenced
measurements on 2 August 2008. The slope
continued to mobilise,
however, but this was slowed and then largely arrested in due course
by a mix of preventative and remedial
measures taken by Mr Naumann.
These included the installation of piles driven deep into the ground
below his property and the installation
of ground anchors which were
driven from his property into and under the Dias property and secured
to the middle retaining wall
on the Naumann property. After the
construction of the three retaining walls Mr Naumann ceased his
building operations and in due
course this litigation commenced. The
Naumann property today remains essentially in the same condition as
after the cessation of
the building works and the completion of the
measures to stabilise the properties/the slope in 2008/2009. As the
months and years
passed however more and more cracks and structural
damage appeared in the Dias dwelling. Venter’s dwelling was
eventually
demolished and a new dwelling built thereon at the
instance of another owner. The same fate befell the Stylemark
property. The
Dias’ continued to inhabit their property.
Chronology
of events
[18]
What
follows is a more detailed chronology of events. It is drawn largely
from Mr Naumann’s account of his excavation
and building
operations followed by the remedial measures which he took. In many
instances the accuracy of the account is disputed
by the plaintiff.
For the purposes of this judgment, however, and subject to the
aforesaid qualification, the timeline will suffice
to give a general
indication of the chronology of the main events:
1.
1980’s

Venter property excavated and developed.
2.
Oct
93 to May 94
Dias property is excavated and developed: fill/rocks placed on
boundary with Naumann property.
3.
05/07/94
Dias’ Loffelstein retaining wall erected.
4.
05/05/05
Moroff and Kuhne (M&K) appointed as the structural engineers and
responsible person for the proposed
works and excavations on the
Naumann property.
5.
05/03/2008
Monterama commences excavations on Naumann property for the three
retaining walls – this involved the removal of
3932.5m³
of earth
and
58
blasting shots
by Shotmaster.
6.
25/03/08
Monterama commences Venter excavations next to his garage which
involved the removal of
574m³
of earth
and
22
blasting shots
.
7.
26/03/08
Completion of excavation by Monterama on the Naumann property save
for the later excavation for the lift
shaft.
8.
After
26/03/08     Naumann commences trimming
excavation for top retaining wall by hand.
9.
02/04/08
Completion of Venter excavations and completion of shot blasting on
Naumann property and near back boundary.
10.
08/04/08
Monterama completed removal from Naumann property of most excavated
material. Rest (mainly large pile of broken
rocks), moved to bottom
level, removed end July after lift shaft excavation.
11.
08/05/08
Naumann digging a trench for the shear key for the top retaining wall
just
below the boundary with the Dias’ property.
12.
22/05/08
M&K express concern about safety issues relating to the Dias’

Loffelstein wall and propose shoring it up or cutting the slope.
13.
27/05/08
Naumann casts foundation for the top retaining wall, the lower
retaining
wall and for a brick wall on the Venter boundary.
14.
Just
before 07/06/08    Mrs Dias sees ‘
furrows
in my front lawn which I thought were moles’
15.
09/06/08
The Loffelstein wall on the Dias property largely collapses against
shuttering
erected for the casting of the top retaining wall on the
Naumann property.
16.
Naumann
casts foundation for his middle retaining wall, the concrete wall on
Venter boundary, and casts the first lift of the bottom
retaining
wall.
17.
26/06/08
Naumann casts:
·
2
nd
lift of top of retaining wall
·
1
st
lift of middle retaining wall.
18.
14/07/2008
M&K appointed by Venter to inspect and report on various cracks
that had appeared in his
property and inspects the Venter property
with him.
19.
Monterama
commences the lift excavation on Naumann property which involves the
removal of a
further
1396.5m³
of material over the next few days.
20.
15/07/2008
Partial collapse of side of lift excavation on Naumann property
followed by an exchange of emails
between M&K and Naumann
regarding this.
21.
17/07/08
Monterama completes lift excavation on Naumann property involving a
further
1480m³
of bulk material being removed off site.
22.
22/07/08
Naumann casts second lift of bottom retaining wall which is
completed.
23.
23/07/08
Mrs Dias is told by her mother that the pool rail has detached from
the
house and a hairline crack appears in the pool.
24.
Cape
Geomatics (Ms Papanicolaou), commences a survey on the Venter
property and at the request of Mr Van Wieringen monitors Naumann’s

retaining walls.
25.
25/07/08
Naumann casts second lift on middle retaining wall, completing it and
casts
first lift on concrete wall on Venter property.
26.
26/08/08
Cape Geomatics commences monitoring of Venter and Naumann properties.
27.
26/08/08
The Dias pool breaks away from the house.
28.
27
– 28/07/08 Heavy rainfall falls over Camps Bay.
29.
28/07/08
A period of major movement in the underlying ground commences and
lasts
up 1 August 2008.
30.
30/07/08
Naumann casts and backfills with concrete behind middle retaining
wall.
31.
31/07/08
Major movement in the underlying ground takes place and City
officials
conduct onsite inspection and issue notice of a dangerous
excavation.
32.
01/08/08
End of major movement period (from 23 July 2008). A meeting of all
parties
is held at the Dias house, including Mr Van Wieringen.
33.
Naumann
appoints Van Wieringen for geo-technical design of any ground anchors
that may be required and instructs a contractor in
this regard,
Fairbrother.
34.
Naumann’s
workmen lay plastic on Dias front lawn and boundary slope.
35.
Naumann
meets Van Wieringen who suggests he may have to backfill site.
36.
03/08/08
Mr Dias falls at the side of the lift shaft excavation on the Naumann
property.
37.
Van
Wieringen leaves a message for Naumann to commence backfilling the
toe of the slip circle on the Venter and Naumann properties.
38.
04/08/08
At Naumann’s request Monterama commences backfilling of both
Venter
and Naumann’s property involving the Venter garages and
the Naumann lower excavation and middle platform with a total of
1057.5m³
39.
17/08/08
Naumann appoints Fairbrother for installation for ground anchors.
40.
18/08/08
Fairbrother commences work.
41.
05/09/08
Van Wieringen recommends the grouting of cracks on their property to
the
Dias’.
42.
26/09/08
Naumann requests that grouting proceeds on the Dias property.
43.
End
Nov 08   Fairbrother completes installation of 21 anchors
and three drains on the Naumann property.
44.
22/01/09
Geomatics survey shows no further movement on Naumann property.
45.
Feb
– Oct 09  Naumann engages Fairbrother to install 42 piles
and further anchors on the Naumann property at substantial
cost for
further stability.
46.
Oct
2009        After installation of
ground anchors and piles on Naumann property, movement
of slope in
direction of Naumann property has effectively stopped.
47.
27/10/09
Dias issues summons.
The
Issues
[19]
The
first issue, whether a common law duty to provide lateral support to
the plaintiff’s property was owed by the first and
second
defendant’s properties, is largely a question of law. The
second issue, whether the excavations carried out on each
of the
defendant’s property breached this duty of lateral support,
involves an evaluation of the factual evidence and the
expert
evidence whilst applying the law. The third issue, namely, assuming
that there was a breach of the duty of lateral support
by one or both
of the defendants, did the scree slope, on which the plaintiff’s
property and residence was situated, mobilise
and subside in or about
June 2008, encompasses the question whether the slope mobilisation
relied on by the plaintiff, namely a
slip circle failure (with uplift
at the toe), occurred or not but also the question of whether such
slip circle failure is a manifestation
of a lateral support failure.
Answering this question, which has a large element of overlap with
the second issue, similarly involves
an evaluation of the factual and
expert evidence and the application of the appropriate legal
principles.
The
Evidence
[20]
The
plaintiff and his wife both testified. Also called on behalf of the
plaintiff were two neighbours, Messrs Wentzel and Babrow.
The
plaintiff called three expert witnesses, Ms Papanicolaou on the
survey process and the results, Dr McStay a geo-technical scientist

who offered his opinion on the central question of the causes and
mechanism of the slope failure and an engineer, Mr Van Gyssen,
who
testified mainly regarding construction issues relating to the Dias
property.
[21]
On
behalf of the first defendant Mr Naumann testified mainly regarding
factual issues. A geo-technical engineer, Dr Day gave expert
evidence
on behalf of the first defendant regarding the mechanism and the
causes of the slope failure and offered an opinion regarding
the
question of lateral support in relation to these matters (as did
Dr McStay).
[22]
The
first third party, Moroff, aligned itself with the case presented by
the first defendant. It called no factual witnesses and
chose not to
place the evidence of its expert, Dr Moffet, before the Court.
Summary
of the evidence
[23]
I
propose firstly to summarize what I regard as the relevant evidence
and, in some cases, to immediately evaluate the witnesses
in
question. In doing so I must emphasise that such evaluations have
been made after a consideration of all the evidence heard
and in the
light of the arguments advanced by counsel in relation to witness
credibility.
The
Plaintiff’s Case
Mr
Kenneth Wentzel
[24]
Mr
Wentzel, a resident of Theresa Avenue and direct neighbour to Mr
Peter Babrow, testified that he had acquired his current property

some ten years previously. Prior to that he had arrived in Camps Bay
23 years previously and in all this time had lived in various

properties on Theresa Avenue which he would develop and on sell.
Around 2002 he went onto the Dias property and spoke to the plaintiff

regarding a possible purchase but the Dias’ were not
interested. Although Mr Wentzel carried out no real inspection

of the property on that occasion he noticed no flaws in the house
although the pool was somewhat green and dirty and only half
filled
with water. He had never experienced any structural or cracking
problems with any of the properties that he purchased on
Theresa
Avenue. Nor had he ever received complaints from the persons who
purchased such properties from him. In 2008, he had attended
the
general meeting at the Dias house where Mr Naumann and engineers were
also present to discuss the slope failure. On that occasion
he saw no
damage to the Dias property although he did not specifically look for
cracks. As mentioned, Mr Wentzel testified that
his property was not
affected as a result of the excavations on the Venter and Naumann
properties. He did testify of being aware
that after the excavations
on the Naumann property his neighbour Babrow had ‘
definite
damage to the Llandudno side of his property’
.
Mr Wentzel also testified that it was a very wet winter in 2008 with
high ground water levels.
[25]
Mr
Wentzel’s evidence was of a rather general nature and when
pressed for detail in his evidence he became defensive. Nonetheless,

I accept the general thrust of his evidence which was that as a
long-time owner of various properties in Theresa Avenue he had
never
encountered any structural problems and that, in 2002 at least, the
Dias property had, on casual observation, been in good
condition.
Mr
Peter Babrow
[26]
Babrow
testified that he resided at 30 Theresa Avenue alongside the Dias
property, having bought the property in about 1998. He
renovated what
had been an old house but in very good condition. He had not been
aware of any structural issues regarding his property
which was in
immaculate condition after his renovations. He and other neighbours
signed an agreement with Mr Naumann relating to
the latter’s
construction of a proposed dwelling. He did so because Mr Naumann was
a master builder with a good reputation.
[27]
That
agreement, also signed by the Dias’ and other neighbours,
provided that they agreed to support Mr Naumann and the first

defendant in an application lodged with relevant departments of the
City of Cape Town and the Western Cape Provincial Administration
for
the removal of a restrictive title condition which affected the
proposed construction. In paragraph 2.7 Mr Naumann and the
first
defendant undertook to ensure the ‘
security
and integrity of neighbouring properties during the construction
phase’
in
return for which the first defendant and plaintiff would build in
accordance with certain annexed plans.
[28]
Some
weeks or months after the excavations on the Naumann property in
2008, Mr Babrow and his partner noticed that their garden
had
subsided. Thereafter he noticed that on the Llandudno side of his
house i.e. alongside the Dias property his deck was cracking
as were
walls in various rooms on that side of the house. He contacted his
insurer who sent out a team and appointed a geo-technical
expert.
That person together with Fairbrother, a specialist contractor,
commenced extensive remedial work at his house. Prior to
2008, he had
never experienced any such problems either with his garden or his
house.
[29]
Mr
Babrow also testified about the state of the Dias property based on
visits he had made there prior to 2008 and in looking after
the Dias
property whilst they were in Zimbabwe. He stated that the condition
of their property was very similar to that of his,
namely, pristine
inside. He testified that he always takes note of such things when he
goes into people’s houses because
he likes things ‘
to
be right’
,
and in fact he would have asked the Dias’ when they were going
to repair something if he saw that it was not in order. He
testified
that on occasion the Dias’ swimming pool was dirty and needed a
water top-up but that he never saw any cracks in
it and would have
raised it with them if he had. After the excavations and subsidence
in 2008, Mrs Dias would call him over if
a new problem arose. As a
result he had gone into the Dias property quite regularly when a new
crack or something similar had become
evident. Mr Babrow testified
that the walls in the Dias house and tiles had cracked, the pool had
become severed from the house,
the garden had dropped as well as the
brick paving outside their respective garages.
[30]
In
cross-examination, Mr Babrow firmly rejected the suggestion that
there had been cracks in the Dias’ pool prior to 2008.
When it
was put to him that the Dias property had been in a fairly
dilapidated state he stated that he could not testify about
the
outside, but the inside was ‘
pristine’
.
He clarified that on most occasions when he had seen the pool on the
Dias property it had been sparkling clean but on other occasions,

when the Dias’ were away, it had been green. He had never seen
the pool completely empty.
[31]
Babrow
was a very good witness who answered questions forthrightly and
without hesitation. His evidence was honest and concise and
I have no
hesitation in accepting it in full.
Mrs
Liliana Dias
[32]
Mrs
Dias, 64 years of age at the time of the trial, testified that she
and the plaintiff came to Cape Town in 1991 and purchased
the vacant
erf at [...] T. A. in order to build a home there. A nearby dwelling
had just been completed and so they engaged the
architect, engineer
and builder who had built the dwelling which they admired. She was
taken through a series of photographs showing
the progression of the
construction of their house. They showed inter alia a huge boulder
being removed in preparation for building
and the foundations for the
back boundary wall i.e. that closest to Theresa Avenue, being
prepared. The witness identified photographs
showing the deep hole
dug on the property to hold but one of the very substantial
supporting pillars for the dwelling, also known
as footpad pillars.
Stones and earth (‘
fill’
)
were put on the edge of the property towards the Llandudno side,
towards the bottom to form a slight bank. No additional rocks
or
earth were brought onto the property. After complaints from Mr
Naumann about rocks falling onto his vacant erf these were removed

and her engineer, a Mr Gadomski, was commissioned to design a
Loffelstein wall in front of the stone bank. Mr Gadomski produced
a
design and the Loffelstein retaining wall was duly built. It stood
from 1993 until 2008 without any problems. The Dias’
moved into
the house towards the end of 1995. The dwelling comprised various
rooms on the ground/basement floor, a middle floor
comprising,
amongst others, four bedrooms as well as a patio and swimming pool.
The top level was a triple garage entering into
a kitchen and
scullery. The dwelling was their dream home and they built it using
the best possible materials.
[33]
The
witness was taken through a series of photographs showing the house
in its newly finished form and through the ensuing years.
She
testified that they experienced no problems in the house from 1994
until 2008. The only flaw she could recall was one tile
on the steps
to the dining room which had cracked. The house had been in extremely
good condition with no mould and the garden
had likewise also been in
good condition.
[34]
Regarding
the pool, Mrs Dias testified that since she and her husband were away
in Zimbabwe for several months at a time the pool
would have to be
regularly cleaned and refilled upon their return. In regard to the
agreement which she and other neighbours concluded
with Mr Naumann
she testified that in giving their consent to his proposed
construction plans, she had relied on the fact that
he was a master
builder and would know what he was doing.
[35]
Much
of Mrs Dias’ evidence concerned her perception or experience of
what took place on the Naumann property during the phases
when
excavation took place thereon and the three retaining walls were
built. In this regard her evidence was of a general nature,

superficial and often too subjective to be of any great value. She
testified that she saw many trucks removing soil and rocks,
that she
was aware of blasts which were quite severe and following which she
felt the shock or vibrations. She also testified as
to various large
rocks which were removed from the Naumann property but her evidence
in this regard was somewhat vague and difficult
to follow.
[36]
Of
greater relevance was her evidence that in the first half of May
2008, her late mother had told her that there was dip in the
garden
but that she had been remiss and paid no attention to this. She also
testified that just before her son’s wedding
on 7 July 2008 she
had seen furrows in her lawn which she thought were caused by moles.
These matters had not caused her concern
because at that time she had
‘
no
idea what her ground was showing her’
.
She also testified about noticing a dip in her garden nearby a
feature rock. However it was on or about 23 July 2008 that clear

indications of trouble appeared. On her return from work her mother
advised that the pool rail had popped out of the wall and their
dog
had disappeared. She had a quick look and saw a hairline crack on the
wall between the house and the pool. When she went down
to Barbara
Road to search for her dog and found Mr Venter standing outside his
property with furniture being loaded into a truck
as he vacated his
house. He was beside himself and showed her large cracks in the
garage floor on his property. Mrs Dias then realised
that what had
been happening on her property was related to the excavations and
work being conducted on the two properties below
hers i.e. the Venter
and Naumann properties, and that for two weeks no one had told her
anything about it. The following morning
she telephoned Mr Naumann to
raise the matter and he advised that he would come up the following
day with his engineer to conduct
an inspection, which apparently he
did do in her absence. On 25 July 2008, a day or so later, the pool
on her property actually
began to break away from the house.
[37]
Regarding
repairs to her house Mrs Dias testified that just before her son’s
wedding (7 July 2008) she had asked her husband
to tidy up a piece of
masonry that had fallen off above a structural beam.  As far as
further repairs were concerned she testified
that after she had
appointed Mr Van Wieringen he had advised her not to undertake any
repairs, to put stickers on all the cracks
as they appeared and to
record notes as to when they did. She had followed his advice ever
since. Mrs Dias confirmed that her pool
had never been repaired prior
to the excavation and that thereafter the cracks in the pool were
grouted by Mr Naumann’s contractor,
Fairbrother.
[38]
Much
evidence and cross-examination was heard regarding a crack in the
Dias’ swimming pool based on what initially was the
first
defendant’s case viz that it had pre-dated the Naumann
excavation. In his first report the first defendant’s
expert,
Dr Day expressed the view that a grouted crack in the pool pre-dated
the excavations but he later abandoned this portion
of his evidence.
Photographs of the pool, post excavation, and an inspection in loco
revealed extensive damage to the pool in the
form of cracking and
severance from the house.
[39]
Mrs
Dias was also shown photographs showing large cracks which had formed
in her garden and which were later grouted by Naumann’s

contractor, Fairbrother, with a mixture of cement and water. She also
testified that the ground in front of the feature rock had
dropped
considerably as a result of the subsidence of the Dias property.
[40]
Mrs
Dias testified further that the paving in front of their garage on
Theresa Avenue had no cracks or indentation prior to the
excavation
but that this had manifested thereafter. She testified of extensive
damage to her dwelling following the excavations
in the form of
cracked tiles, cracks in the concrete slabs from corner to corner,
doorframes shifting, numerous cracks in the wall,
windows being
twisted out of place and bathroom units pulling away from the walls.
At the inspection in loco numerous cracks in
most of the rooms were
pointed out, marked by pieces of masking tape which, the witness
testified, had been put up by her and on
which she had recorded the
dates when the cracks had appeared.
[41]
Under
cross-examination it was put to the witness that the Loffelstein
retaining wall on her property had not been properly constructed
and
had no foundation. Her response was to disagree and to point out that
the wall had stood for 15 years without any problems
and had been
built according to an engineer’s plan. Mrs Dias advised that
the engineer, Mr Gadomski, could not testify in
this regard since he
was now an elderly man and no longer capable of giving evidence. She
added that following its collapse hundreds
of the Loffelstein bricks
forming the wall had disappeared and must have been taken away at Mr
Naumann’s instance. It appears
to be common cause that when the
Dias’ Loffelstein wall collapsed into Mr Naumann’s
excavation, he never informed them
of this nor complained that it was
not properly built. He used the Loffelstein bricks as fill and
proceeded with the building of
his upper retaining wall. It was also
put to Mrs Dias that a storm water pipe which had admittedly
pulled away from the house
as a result of the subsidence and had been
repaired by Mr Naumann indicating that there had been previous
subsidence and repair.
The witness disagreed with this proposition.
[42]
During
cross-examination on behalf of the first third party, it was put to
Mrs Dias that the wall and embankment raised the front
of her
property above the natural ground level. The witness disagreed
stating that this was just on one corner on the Llandudno
side. She
further testified that following the excavation on the Dias property
in 1993 prior to construction at the boundary with
Theresa Avenue, a
lot of rocks and earth were taken off site rather than being moved to
the garden of the property i.e. on the
seaside.
[43]
When
Mrs Dias testified about matters within her direct knowledge her
evidence was clear and credible. However, under cross-examination
she
repeatedly jousted with the cross-examiner and attempted to argue her
case rather than simply give direct answers. What became
clear was
that prior to the subsidence and its consequences manifesting on her
property she had paid little attention to what was
taking place on
the Naumann and Venter properties. Another hallmark of her testimony
was a distinct tendency to magnify events
relating to the excavation
on the Naumann property and subsequent developments or to put a slant
on them in favour of her view,
no doubt sincerely and strongly-held,
that it was this excavation which had caused all the problems which
she and her husband had
endured ever since 2008.
Mr
Artur Dias (the plaintiff)
[44]
Mr
Dias was 77 years old when he testified. He is a qualified toolmaker
who was born and brought up in Portugal. He learnt English
only in
his late twenties or early thirties. Mr Dias spoke in heavily
accented and less than fluent English and stated that he
communicated
with his wife in a number of languages. Mr Dias testified that he
visited his Camps Bay property regularly while the
dwelling was being
built. He was there when the foundations were dug, as were the
architect and engineer. Huge rocks were excavated
and taken to the
road to be removed in order to ensure no damage to neighbours’
properties. When his house was completed
in 1992/1993 he was very
proud of it and it was in very good condition – ‘
more
or less 100%, yes’
.
His walls were not damaged at all and everything worked in the house
including the doors and windows. His pool never had any leaks.
From
time to time there was not much water in the pool because he would
try to clean it upon returning to Camps Bay after long
periods of
time in Zimbabwe. The wind in Camps Bay would deposit a lot of dust
and leaves into the pool and normal cleaning did
not work. He
testified that his garden had been in excellent condition and the
irrigation and sewerage systems had worked. Mr Dias
could not
remember when the excavation on the Naumann property started but he
remembered seeing large machines excavating and many,
many trucks
taking the fill away. On one occasion he had sat on top of his
Loffelstein retaining wall and observed Naumann’s
employees
excavating huge rocks, some of them very close to his property. He
had said to Mr Naumann on that occasion that the latter
was digging
under his ground and would damage his property but Mr Naumann told
him that he must not worry because he knew what
he was doing.
Regarding the Loffelstein wall he testified that 80% of it had
collapsed as a result of the excavations on the Naumann
property but
that 20% remained to this day. Hundreds of the Loffelstein blocks
disappeared and he never saw them again. Mr Dias
also testified about
the crack in the dining room which was repaired after the excavations
had commenced around the time of his
son’s wedding and which
his wife had referred to in her testimony. He testified that after
his son’s wedding when he
came back home there was another
crack in the corner of the dining room.
[45]
Mr
Dias testified further about the damage suffered to his house after
the 2008 excavations. These included cracks all over the
house, the
garden sinking and cracks appearing therein, the sewerage and
irrigation systems breaking, the pool moving away from
the house and
cracking to an ever greater extent. He and his wife had called Mr Van
Wieringen to take a look at the crack between
the pool and the house
and he had advised that they should cut the reinforced steel joining
the pool to the house to take the pressure
off the house. Mr Dias did
this. He had attended the joint meeting at his house at the beginning
of August when Mr Naumann and
various engineers were present. No one
had mentioned his skylight being broken or water leaks at his
entrance, allegations which
were made years later by Dr Day. At that
time there had been no cracks in his lounge and only the two cracks
in the dining room.
He testified that his lounge presently had 100
cracks and his dining room 52 cracks, some of them from the ceiling
to the tiles.
Some were horizontal and some vertical. On the entrance
wall alone there were seven cracks. Mr Van Wieringen came back to his
house
when the pool showed more cracks and he showed him the cracks
in his house. He saw another two cracks in his TV room downstairs
and
cracks near some small windows. His wife started putting tape on
these cracks and he in fact had to purchase a high step ladder
to put
tape on cracks high up on the walls. Mr Van Wieringen also advised
him to have the cracks in his garden grouted and at the
same time to
have the cracks in the pool so treated. Mr Dias testified that the
contractor appointed by Mr Naumann, who did the
grouting, was
Fairbrother and that its foreman told him to supervise the workers
doing the work. They were given rods about 3m
long which they would
put into the cracks in the garden to open them up so that more
slurry, the water and cement mixture, could
be pumped into the
cracks. At some stage the foreman showed him the book in which he
kept records of the process and indicated
that 565 bags of cement had
been pumped into cracks in his ground. This figure was not disputed.
[46]
Mr
Dias testified about the paving in front of his garage adjacent to
Theresa Avenue. There had been no problem there before 2008.
After
the excavations he noticed a slight depression there but not as much
as is now depicted in photographs. Later, when the rains
came it
became deeper and deeper with a similar process occurring on his
neighbour, Mr Babrow’s, driveway.
[47]
Mr
Dias testified that after 2008 his skylight started cracking with
water leaking through the ceilings at the entrance to his house.
He
had tried to fix the ceilings and had used buckets to catch the
water. The worst problem was that when it rained the water runs
from
Theresa Avenue to the bottom of his house, going through the ceiling
and into the maid’s room and into the kitchen.
Two weeks before
testifying half a square meter of the ceiling in the kitchen fell
down. The witness produced a sample of that
fragment which is
Exhibit
1
.
As far as repairs were concerned he had tried to repair only one
crack in the maid’s room and tiles on the veranda which
had
caused leaks into his daughter’s bedroom.
[48]
Mr
Dias also confirmed that he had been taking photographs on the public
servitude ground alongside the lift shaft excavation on
the Naumann
property when the earth under his feet had collapsed and he fell. He
had suffered concussion and had to be removed
for medical treatment.
[49]
Much
of Mr Dias’ evidence was largely uncontroverted. He stood firm
against repeated suggestions that there had been pre-existing
damage
to the Dias property in the form of at least one major crack in his
pool. Ultimately he was fully vindicated in this evidence
when Dr Day
abandoned his argument that at least one of the cracks in the pool
must have existed prior to the events of June 2008.
The main thrust
of Mr Dias’ evidence was that his dwelling had been in
excellent condition prior to June 2008, so much so
that he took great
pride in it and that all the damage which it had sustained followed
the excavations on the properties below
him. He came across as a
straightforward and entirely credible witness. On several occasions
during his evidence he invited any
experts appointed by the first
defendant and the first third party to examine his house in greater
detail to see whether there
was any evidence of pre-existing damage
to his property. During Mrs Dias’ evidence when it appeared
that her husband might
not testify for one or more reasons, including
his weak English, much criticism and scepticism that his evidence
would support
hers was expressed on behalf of the first defendant and
the first third party. This evaporated when Mr Dias testified
regarding
pre-existing conditions on the Dias property. I have no
hesitation in accepting his evidence in full which also confirmed his
wife’s
evidence on this score.
Dr
John McStay
[50]
Dr
McStay was called as the plaintiff’s principal expert witness.
He described himself as an engineering and environmental
geologist
with 23 years of consulting experience. Much of this was in
geo-technical site investigations and ground engineering
for
buildings, major infrastructure, roads, ports and harbours. He holds
a BSc in Geological Sciences from a UK university and
a Doctorate of
Philosophy from UCT. He has an impressive professional CV. Dr McStay
has been in practice since 1992 but emphasised
that he was not a
consultant engineer. He is presently a director of WSP Environmental,
a large international engineering consultancy
firm of which he is a
director and in charge of the geo sciences unit.
[51]
In
his first written opinion, Dr McStay’s overall opinion was that
the slope failure was an inevitable result of the excavations

undertaken on the Naumann and Venter properties ‘
given
the extent of the soil removal’
and that it was not triggered by pre-existing or additional loads
from the structures on the Dias property. He wrote that the Dias

property is situated on the seaward facing hill slope of Table
Mountain on the second highest terrace of Camps Bay. The ground

conditions consist of a considerable thickness of boulder talus, a
transported soil deposit consisting of erosional debris from
the
mountain side. The talus soil contains coarse grain pebbles and
massive boulder-sized rocks of sandstone in a silty and clayey

matrix. The thickest talus deposits tend to form in gully features
and represent localised historic landslide deposits and can
be
re-mobilised if disturbed. Natural soil slopes tend to be stable at a
slope angle of between 45 degrees and 60 degrees. Slope
failures can
be triggered by heavy rains, loss of stabilising vegetation cover
(fire damage) and by removal of lateral support.
He opined further
that construction on the mountain slopes of Camps Bay requires a
cautious approach by experienced professionals.
Dr McStay reviewed
the remedial measures taken subsequent to the excavations, notably,
the installation of ground anchors and expressed
the view that the
installations of such anchors below the foundations of an existing
building is a relatively extreme solution
only undertaken when the
ground instability would be regarded as so severe that structural
failure of the building is considered
to be a likely outcome. In his
view this was the only practical remedial option available to
stabilise the slope. In his further
opinion the magnitude of lateral
and vertical instability observed on the Dias property resulted in
the geo-technical engineer
utilised by all the relevant parties at
the time, Mr Van Wieringen, applying a series of ‘
last
resort remedial engineering measures in order to reduce instability
and safeguard the property’
.
In his further opinion Dr McStay expressed the view that the slope
failure and ground movements represented a predictable consequence
of
‘
unsupported
excavations works and removal of lateral support’
.
He expressed the further view that poor ground conditions, worsened
by winter ground water flows, were destabilised by the excavation

works resulting in the removal of lateral support to the Dias
property and consequential subsidence and slope failure. He also
was
of the opinion that the ground movements and structural damage
experienced on the Dias property were the result of a progressive

series of slope failures forming what are termed ‘
en
echelon slip planes’
i.e. a complex series of roughly circular failure planes developed in
a large mass of overstressed soil. To the suggestion that
the Dias
property was no longer in its natural state, he expressed the view
that in the built environment it is inherent that the
natural ground
has been modified to enable development.
[52]
Regarding
the suggestion that the stability of the Dias property was
compromised by the development thereon and/or the development
on
neighbouring properties, Dr McStay observed that no such
instability had been observed until 2008. In response to the
suggestion that the defendants owed no duty of lateral support to the
owner of developed land, Dr McStay pointed out that the large
scale
excavations had resulted in the subsequent slope failures and ground
movement and these were entirely predictable. He pointed
out further
that the South African Lateral Support in Surface Excavation Code of
Practice (South African Institution of Civil Engineers
Geo-technical
Division, 1989) (‘the Lateral Support Code’) states that
lateral support must be given to properties
surrounding an
excavation. Regarding the proposition that the plaintiff had loaded
its property by the placement of fills at the
front thereof, Dr
McStay opined that the Dias property was stable at the time of
excavation and the terraforce block wall thereon
(the Loffelstein
wall) and the configuration of the Dias property constituted
‘
perfectly
reasonable measures typical of many residential properties in Camps
Bay, placing no significant risk on the properties
downslope’
.
[53]
Dr
McStay issued a revised opinion after the trial had commenced on the
basis that he had only had access to limited documentation
when he
filed his original expert summary. He repeated his initial conclusion
that the movement of the Dias property was occasioned
as a result of
the removal of lateral support on the Naumann property when the
excavations thereon were undertaken. He expressed
the view that Mr
Naumann had been under an obligation to consult an appropriately
qualified geo-technical expert in order to investigate
the extent to
which his excavation might impact on the lateral support provided to
his neighbours and the Dias property in particular.
In his view the
advice which he would have received would almost certainly have been
to reduce the scale of the excavations and/or
to provide ground
anchors and/or piles to ensure not only continued lateral support to
the Dias property but indeed the structural
integrity of the Naumann
property and the structures to be constructed thereon. He expressed
the view that no instability to the
Dias property subsequent to the
construction of the Dias residence was occasioned by the pre-existing
excavations on the Venter
property until after the lateral support
provided by the ground on the Naumann property was removed by the
excavation thereon.
Somewhat contentiously, Dr McStay revised his
initial opinion that the most recent excavation on the Venter
property had played
a role in the subsidence. On reconsideration he
expressed the view that it a played a minimal, if any, role in the
ground subsidence.
In effect, as I understood his evidence, he was
expressing the view that both historic and more recent excavations on
the Venter
property had played no role in the destabilisation of the
Dias property.
[54]
He
again expressed the view that the Dias property mobilised as a
progressive series of slope failures. These failure planes had

created the cracks which were subsequently filled with grout until
they were largely arrested by the foundations of the Dias house.
He
regarded the final uppermost tension crack as that along the entrance
paving between Theresa Avenue and the Dias house although
he found it
not possible to state whether that crack was cause by a further
failure plane or by the tilting of the Dias house consequent
upon its
settlement. In his supplementary report Dr McStay observed that all
told some 5413m³ of earth had been removed from
the Naumann
property in the excavation. This was the equivalent of approximately
9743 tons of earth which he regarded as a very
significant quantity
from a comparatively small property on the slopes of Camps Bay.
[55]
Dr
McStay again observed that the Dias property had stood unaffected for
at least 16 years prior to 2008 and that there was no evidence
that
any of the other properties or their initial excavations caused any
damage to the property prior to 2008 and that it was only
after the
major excavations on the Naumann property that the mobilisation of
the Dias property commenced.
[56]
Dr
McStay testified that given the nature of the historic landslide
deposits on the Camps Bay mountainside, their variability and

thickness, the slope is prone to erosion and failure. This means that
a cautious approach should always be followed for excavation
and
construction on that mountainside. Most failures that geo-technical
practitioners have to deal with are related to excavation,
being the
removal of lateral support. In Dr McStay’s professional career
the excavation on the Naumann property constituted
a very large
excavation for a private property.
[57]
Dealing
with the effect of the excavation on the Venter property, Dr McStay
relied on the discrepancy of the volume removed (compared
to the
Naumann property) and also with the inability to establish a
timeframe suggesting that the Venter property excavations had
played
a role in the general subsidence. His opinion was, however, itself
qualified i.e. that ‘
if
it was anything it was a minor contributory factor to the eventual
collapse’
.
As regards the Loffelstein wall, he testified that it was, to his
understanding, built to prevent loose material falling onto
the
Naumann property i.e. erosional protection and that the additional
load it created, as well as the fill, was ‘
relatively
minor’
.
He explained that one of the differences between his opinion and that
of Dr Day’s related to the mechanism of the surface
failure and
in particular whether it was a main circular slip or whether it was a
series of smaller slip planes immediately behind
the face of the
excavation, namely, a progressive failure as opposed to a deep seated
slip circle. He made the further point that
the existence of a deeper
slip circle had not been demonstrated independently and by geological
investigation. Both conclusions
were in effect inferences which had
been drawn. Commenting further on the two contrasting explanations,
Dr McStay testified
that in his view they both resulted from the
removal of lateral support because the mechanism in each case was the
same. Dr McStay’s
opinion was that the cause of damage was the
extensive excavations and their location (on the Naumann property)
which amounted
to ‘
the
removal of lateral support in the form of the earth and that was the
main triggering mechanism for the slope instability. Whether
that is
a series of small progressive failures behind that excavated site
plus the triggering of other deeper failure, appears
to be largely
irrelevant in terms of the actual (indistinct) mechanism itself. That
mechanism was obviously impacted by winter
rains, but that was
entirely foreseeable. It appears that the timing of the failure was
related to the failure to actually secure
those retaining walls in
time before winter seepage actually got behind the upper most
retaining wall’
.
[58]
Dr
McStay also testified that the heavy rain that occurred at the end of
July/beginning of August 2008 would have been in the order
of
something that one would have expected every two years or every five
years ‘
probably
something in the order of a one in 5 year event’
.
He added, however, that it would certainly be ‘
within
the design consideration for any structures on the hillside to
maintain adequate drainage during construction and then after

construction to deal with that degree of rainfall. So you could
certainly not put this into a category of act-of-God, storm events’
.
[59]
In
regard to Dr Day’s opinion and, for that matter, the revised
opinion of Mr Van Gyssen, that, in engineering terms, the
retaining
walls constructed on the Naumann property had served their function,
Dr McStay made the point that in the context of
the present matter
the function of the retaining wall or walls was to retain the earth
behind it and by inference the property
behind that as well but that,
‘
in
this instance, although the concrete of the wall is still intact, it
did not perform its primary function of retention. It did
not provide
sufficient lateral support to stop lateral and vertical movement of
the soil and damage to the Dias property, therefore
it was not fit
for purpose’
;
further in this regard, the retaining walls on the Naumann property
had been in a state of failure because otherwise they would
not have
needed the remedial measures which were put in place, namely, the
anchoring and buttressing.
[60]
Regarding
the ground fissures and the grouting which the ground subsidence
necessitated, he testified that the fissures were so
wide that the
contractor could simply mix cement with water and pour them into open
cracks on the ground. This he testified was
‘
fairly
unusual and particularly when you look at the volume of cement used’
.
The cement mixture, he testified acted as ‘
a
glue binding onto the soil and increasing the friction between soil
particles. It is what we would call soil improvement. But
at the same
time it is adding considerable amount of mass to an already unstable
slope condition’
.
He added that the cracks ‘
would
appear to be relatively deep, 5 meters or so’
.
Dr McStay testified that the Dias house itself did not appear to have
undergone extreme lateral movement but rather relatively
small scale
vertical settlement leading to the conclusion that the original
foundation of the house was largely below the active
slip circle
causing the lateral movement. He agreed, as Dr Day had observed, that
the building is now generally tilted northwards
towards the original
excavation on the Venter property and it was behaving as a rigid mass
and certainly showed no signs of having
‘
broken
its back’
by having structural failure through its columns or slabs. Regarding
the crack in paving between the garages of the Dias property
and
Theresa Avenue, Dr McStay testified he regarded it as the ‘
final
expression of this disturbed ground behind the failure surface’.
He
noted that this movement was extensive, running across two properties
and involving damage to a wall and therefore must have
a broader
cause which he regarded as settlement related to a vertical downward
movement rather than just uplift. Dr McStay also
testified that the
fact that excavations on the Naumann property stood for some time
before they affected the Dias property was
not surprising.
[61]
By
the completion of his cross-examination, Dr McStay remained of the
opinion that the deep seated movement under, inter alia, the
Dias and
Naumann properties was a slope failure triggered by the removal of
lateral support. His further opinion was that the timeframe
for the
slope failure coincided with the commencement and the bulk of the
completion of the excavation. This occurred over a period
and was not
a single definitive event in time. As he put it ‘
it
must have actually commenced before measurements were taken,
otherwise the measurements would have never taken place, the slope

was already in failure… the slope does not fail immediately in
that fashion on deep-seated circle of this nature. It fails
over
time’
.
Challenges
to Dr McStay’s evidence
[62]
Dr
McStay was cross-examined at length and his evidence was heavily
criticised by counsel on behalf of the first defendant and the
first
third party. Mr Dickerson, for the first defendant, submitted that
the only material conflict of opinion between Dr McStay
and Dr Day
was the former’s contention that the slip circle slope failure
was caused by the removal of lateral support in
contrast to Dr Day
who contended that it was not. But he argued that Dr McStay’s
qualifications and expertise in relation
to the subject of his
professional opinion were sorely lacking; further that he was neither
independent not objective, had tailored
his evidence to suit the
plaintiff’s case and had ventured an opinion on legal matters
in respect of which he had no qualifications.
[63]
His
argument regarding the inadequacy of Dr McStay’s qualification
was based on the contention that although he purported
to testify as
a consulting engineering and environmental geologist he was precluded
from doing so because he was not registered
as a natural scientist
under the
Natural Scientific Professions Act 27 of 2003
and that in
performing such work, Dr McStay was in fact committing a criminal
offence under the provisions of the Act.  It
would appear that
Dr McStay’s professional qualifications do not meet the
requirements for registration of the South African
Council for
Natural Scientific Professions. The second basis for the first
defendant’s attack on Dr McStay’s qualifications
was that
he was not an engineer and therefore not qualified to express some of
his opinions.
[64]
In
P
v P
,
[1]
it was held that it is the function of the judge to decide whether
the witness has sufficient qualifications to be able to give

assistance. I would add that I do not see it as the function of the
Court to determine whether a particular expert witness has
complied
with all the professional and legal requirements for him or her to
practise in their chosen field and, for want of such
compliance, to
automatically treat such person’s evidence as inadmissible.
That, as I see it, is primarily the function of
the relevant
regulatory or disciplinary body, if necessary acting pursuant to a
complaint. In any event I would expect that if
a party takes the
position that a witness purporting to give an expert opinion is not
qualified to do so then that point should
be raised as an objection
and argued at the earliest opportunity rather than allowing such a
witness’ evidence to proceed
and raising that point
en
passant
in cross-examination without asking for a ruling.
[65]
Having
regard to Dr McStay’s CV, the academic qualifications which he
holds and his professional experience, I am of the view
that he is
indeed qualified to express an expert opinion in this matter.
[66]
The
second tranche of criticism against Dr McStay was based on what was
said to be the superficial nature of his investigations
and
evaluations prior to reaching his conclusions and opinions. In this
regard reliance was placed on his alleged wholesale acceptance
of an
account obtained from Mr and Mrs Dias and his allegedly contrived
attempt to distance himself from the large slip circle
failure as the
mechanism of the slope failure. I certainly do not understand Dr
McStay’s evidence or opinion to represent
a wholesale retreat
from or rejection of the slip circle failure explanation of the
ground mobilisation. In my view, furthermore,
it is not necessary for
the purposes of this matter to determine whether, as Dr McStay would
have it, the mechanism was a series
of
en
echelon
smaller slip circle failures or, as Dr Day would have it, there was
one large slip circle failure. These two mechanisms do not
exclude
each other but appear to overlap and constitute variations of
essentially the same mechanism. Nothing material turns on
the
difference between these two (inferred) mechanisms of slope
mobilisation. Another major ground of criticism of Dr McStay’s

evidence was what was described as his
volte
face
regarding the role of the Venter excavations. Here it was argued that
whereas Dr McStay had initially opined that the Venter

excavation together with the Naumann excavation had triggered the
slope mobilisation, in his supplementary report filed on 3 March
2017
he expressed the view that the Venter excavation had not caused or
contributed to the problem; further that this opinion was
only
expressed after the plaintiff had reached a settlement with Venter
involving payment by the latter of an undisclosed amount
of money. I
shall deal with this criticism when I deal with the issue of lateral
support.
Ms
Valentia Papanicolaou
[67]
Ms
Valentia Papanicolaou is a professional land surveyor who qualified
with a BSc in surveying in 1988 and has practised in that
field ever
since. She is a member of Cape Geomatics CC and specialises in
precise engineering surveying as well as cadastral surveying.
In the
former field, measurements are much more precise, down to
millimetres, and its main application is in the engineering field.

She has been monitoring excavation phases for imminent movement since
2001. Generally, her
modus
operandi
is to arrive on a site once the excavation has reached a certain
level, to then put up initial targets and further targets
progressively
as the excavation deepens. Thereafter, once a week she
will go to the site to take measurements. These measurements of
target movement
give notice of imminent failure of natural support
i.e. the failure of the supporting structures to keep the excavation
in its
place. Large variations in this context would be 10mm which
would be something for her to be concerned about. She has extensive

experience of excavations in Camps Bay, Clifton, Bantry Bay, Sea
Point and Green Point, virtually every large excavation. The reason

for the considerable monitoring done in these areas is because
basement areas are excavated for parking space; secondly, many
excavations are supported laterally by piles, foundations and granite
as opposed to an open excavation and thirdly, because of the

pronounced slope in those areas.
[68]
Her
first involvement in the present case was when Mr Van Wieringen
requested her to start monitoring on the Venter property and
on the
top retaining wall on the Naumann property. She began monitoring on
26 July 2008 and a few days later was asked to go onto
the Dias
property and commence monitoring and measurements there. Later she
initiated measurements on the Babrow property and the
Stylemark
property. Ms Papanicolaou presented a compendious document
setting out all her recordings and measurements. The
X co-ordinate in
the tables represents the movement in the Llandudno to Sea Point
direction or vice versa, the Y co-ordinate reflects
movement from the
mountain to the sea or vice versa and the Z co-ordinate reflects the
vertical lift or fall. Ms Papanicolaou
referred to minutes of a
joint experts meeting held on 22 February 2016 in which the following
was recorded and agreed to by her:
‘
3.
It is agreed that the zone of
major slope movement recorded by the survey between the end
of July
2008 to the beginning of September 2008 included the Naumann
property, the front garden and pool on the Dias property stopping

short of the house, and most of the Venter property stopping short of
the Venter/Stylemark boundary. The direction of the movement
in this
zone is predominantly towards the sea;
4.
There has been a significant reduction in the rate of movement
subsequent to
end November 2008 when the majority of the anchors
through the Naumann retaining walls were installed. The upper
retaining wall
has (sic) subsequently moved up slope by a few
millimetres;
5.
It is agreed that there may have been unrecorded movement prior to
commencement
of monitoring on 26 or 28 July 2008;
6.
It is agreed that the Dias house has moved significantly less than in
the zone
referred to in (3) above and the direction of movement is
mainly towards Sea Point with a lesser seaward component. Babrow’s

house has also moved significantly less than in the zone referred to
above both towards the sea and towards Sea Point i.e. diagonal
to
Barbara Road.’
[69]
Ms
Papanicolaou testified that all of the monitoring points sank by
different amounts except one point which rose indicating that
the
Dias house was not sinking uniformly. She referred to various
movements monitored and measured, one of 206.7mm over a few days

which was such a great distance that at the time she had wondered
whether she was doing her job properly. She was asked if she
saw such
a degree of movement often and her reply was that she had never come
across this before. This was target MO3. At a later
stage the witness
did measurements relating to the Venter property for a new owner who
required such data before he demolished
and re-excavated. She
confirmed that the old Venter structure had been completely
demolished and new one built with piled walls
and lateral support and
in respect of which she had performed monitoring services. She added
that soil anchors were installed and
retaining walls anchored for the
new dwelling on the Venter property.
[70]
The
witness was strenuously cross-examined and criticised at the instance
of the first defendant. Lines of attack were that she
was not
impartial and that she had not disclosed certain levelling data. I do
not regard it as necessary to deal in any depth with
these criticisms
save to state that I was satisfied that Ms Papanicolaou gave evidence
impartially and that she at no stage sought
to hide any of her data
from any party. Another line of attack upon the witness was that she
would not make concessions which favoured
Dr Day’s opinion or
theories. The witness repeatedly replied that she was primarily a
data capturer and not an interpreter
of the movements she captured
and recorded. She conceded that the data she captured represented the
movement of a large piece of
land in the shape of an arc albeit very
roughly so. She testified repeatedly that she was unable to give
explanations on matters
which she had not measured or monitored. Ms
Papanicolaou was the first expert and major witness called by the
plaintiff. My impression
was that the first defendant and first third
party inappropriately strained to make their case through this
witness when in truth
her role was that of a data capturer, albeit a
sophisticated and highly qualified one.
[71]
I
formed a favourable impression of the witness who made every effort
to confine her evidence to the data which she had captured
and to her
discipline of land surveying. I did not gain the impression that she
was partial to the plaintiff’s case or anyone
else’s for
that matter but rather that she did not wish to stray beyond her
field of expertise. The attack on her concerning
her failure to
disclose certain levelling data was in my view not substantiated nor
was the criticism that she would offer opinions
when they were
favourable to the plaintiff but not otherwise.
Mr
Johannes Van Gyssen
[72]
Mr
Van Gyssen is an engineer with a BSc in civil engineering who first
registered as a professional engineer in 1976 and practised

thereafter in Cape Town. His expertise lies solely in the field of
building structures, mainly domestic, commercial and industrial

buildings. He testified that the summaries relating to the opinions
of Drs McStay and Day were of a geo-technical nature and
fell
outside his field of expertise. He testified that he had had regard
to the architectural drawings by the architect who had
designed house
Dias and had satisfied himself that the building had generally been
constructed in accordance with those plans;
furthermore that the
drawings by the structural engineer relating to the dwelling had
indicated the various structural aspects
of the dwelling which
appeared to have been duly executed in construction. He noted that
the building was constructed as close
to Theresa Avenue as possible,
that the building structure was fully framed and consisted of a
reinforced concrete frame with brick
infill panels. It featured
various retaining walls below the house, all of which are integral
with the building structure and that
the building structure was
fairly rigid, this being due to the various components such as
retaining walls, floor slabs, beams,
etc.
[73]
Upon
his inspection in early 2017, he noticed numerous defects in the
building including roof leaks, loose ceilings, numerous internal

plaster cracks and water or damp penetration through walls, deformed
windows and sliding doors, numerous cracked floor tiles, cracks
at
brick and concrete intersections and a severely cracked pool
structure. He expressed the view that at that stage there were
too
many unknowns to conclude that the dwelling was capable of repair. He
observed also that the ground between the edge of Theresa
Avenue and
the Dias house had an obvious crack.
[74]
Regarding
criticisms raised by Dr Day in regard to the lack of movement or
expansion joints in the dwelling he stated that the decision
whether
to install these in a building rests entirely with the appointed
structural engineer and that such joints are not mandatory.
He opined
further that fully framed buildings such as the Dias house do not
normally have such joints and there is no necessity
to have joints
for a building of that size and type of structure. In his opinion,
the building had complied with the National Building
regulations
although with the defects it had suffered since 2008 the building was
no longer compliant in many respects.
[75]
Mr
Van Gyssen expressed the further opinion that the excavations below
the Dias property, i.e. not on its property, caused considerable

ground movement on the Dias property, well in excess of that
recommended. The ground surrounding the house had clearly been
disturbed
and the movement of the house indicated that its
foundations had also been disturbed. The movements which the
structure had suffered
were not of a regular nature such as vertical
settlement only. It had tilted and settled irregularly and it had
twisted. He expressed
the further view that the building was still in
the process of stabilising itself due to the disturbance of the
ground and that
this in turn would lead to further movement. He
opined further that reinforced concrete has some degree of
flexibility, being reinforced
with steel. It will thus tolerate some
degree of movement and will bend or deflect without any real
appearance of being distressed,
up to a point. However this is not
the case for rigid and brittle materials such as the plastered
brickwork, floor tiling, skim
plaster board ceilings, glazing roofing
and roof lights. The original support of the aforementioned rigid and
brittle materials
in house Dias has been disturbed by the movement of
the supporting concrete structure, which movement had been irregular.
[76]
Commenting
on Mr Naumann’s report and criticism that the structure lacked
soft joints, Mr Van Gyssen opined that if any defects
had existed
because there were no soft joints these would have appeared long
before 2008. Cracks to the plaster would have become
apparent within
a few years of construction and would presumably have been dealt
with. He expressed the further opinion that there
was no evidence of
poor building practice and he observed that the original builder,
Douglas Benson Construction, was a master
builder with considerable
experience and that construction of the Dias residence had been
monitored both by the appointed architect
and engineer. He expressed
the further opinion that it was far more probable that the
excavations and subsequent movement of the
structure caused the
damage to the Dias house rather than the defects relied upon as
contained in Mr Naumann’s report.
[77]
Mr
Van Gyssen expressed the view that the allegations in the first
defendant’s experts’ reports that the dwelling on
the
Dias property was poorly designed and constructed was no more than
unjustified speculation. Mr Van Gyssen also prepared a supplementary

report in which he addressed certain issues raised in an expert
supplementary summary of the first defendant’s expert
engineering
witness, Mr Moffet. Since Mr Moffet did not testify, it
is not necessary at this stage to deal with the contents of Mr Van
Gyssen’s
report save in relation to the retaining walls on the
Naumann property.
[78]
Mr
Van Gyssen testified that he had conducted numerous inspections of
cracked or cracking houses. In regard to the swimming pool,
he
disagreed with the suggestion that attaching the pool to the house
was a significant design fault or that the pool had caused
the house
to collapse. In his opinion Mr Van Wieringen’s alleged advice
to saw off some of the steel ties between the pool
and the house was
an act borne of panic. As regards the ground disturbance between the
Dias’ garage and Theresa Avenue, he
disagreed that it was
caused by a lack of compaction stating that the only conclusion he
could reach was that it must have been
the result of the settlement
of the ground due to the 2008 event. He conceded that he had been
unaware that the top retaining wall
on the Naumann property had no
anchors. When it was put to him that the anchors were used to
stabilise the slope and not the walls,
the witness had no comment.
The
First Defendant’s case
[79]
On
behalf of the first defendant, Mr Naumann first testified and was
then followed by Dr Day, the geo-technical engineer proffering
his
expert opinion.
Mr
Michael Naumann
[80]
Mr
Naumann testified both as a factual witness on behalf of the first
defendant but also as an expert witness. In his
Rule 36(9)(b)
summary
he was described as a qualified quantity surveyor with 38 years’
experience in the construction industry. The summary
of his expert
opinion indicated that he would testify that soft joints are required
for the walls of domestic structures such as
the plaintiff’s
dwelling since, if not, there will inevitably be cracking within a
few years as a result of movements in
the materials caused by natural
fluctuations in temperature with the passage of time and seasons. He
was also to testify that no
soft joints were observed in the Dias
house and if present at all must have been plastered over. His
further opinion was that most
of the cracking observed in the
plaintiff’s house was not structural but typical of cracks
which appear as a result of the
omission of soft joints. His opinion
was further that movement or expansion joints are also required in
floors and tiling to allow
for movement caused by fluctuations in
temperature and change in environmental conditions and the omission
of such expansion joints
will inevitably result in cracking within a
few years. His further opinion was that there were no expansion
joints in the flooring
and balconies of the plaintiff’s
dwelling and the cracking in the interior floors and tiling of the
plaintiff’s house
was caused by that omission. He was further
to testify that the majority of cracks in the plaintiff’s house
marked by masking
tape have no structural significance and are
typical of those caused by ‘
incorrect
building practices being followed’
.
Finally, he was to testify that there was evidence of similar cracks
which had been repaired and painted, presumably before 2008.
[81]
When
called, Mr Naumann testified that although he studied quantity
surveying for three years he did not graduate and his CV was

therefore inaccurate in that respect. In 1983 he had started Naumann
Construction and since then he had built about 60 houses in
Cape Town
and factories in industrial areas. Many of the houses were in the
Camps Bay/Clifton area. Since 1987 he has been a member
of the Master
Builders Association. He built, and handed up, a helpful scale model
of the excavation on the Venter and Naumann
properties, also showing
the higher surrounding properties which is
Exhibit
2
.
He is married to Mrs Petropolus (out of community of property), the
first defendant and owner of the Naumann property. In 2003
he and his
wife began to think of building a house on the property and to this
end first he commissioned a topographical plan from
a land surveyor.
In 2005, he met with Messrs Moroff and Kuhne, the consulting
engineers and predecessor to the first third party,
and engaged them
on the project. He also appointed an architect to design the house
but not to oversee its construction. He and
his wife had always
planned that they would build a house on the erf. Building the house
designed required certain title deed relaxations
and to this end he
had meetings with the Camps Bay Ratepayers Association and neighbours
and reached an agreement. These neighbours
included Mrs Dias. On an
occasion in 2006 he had met with Nik Moroff, gone to the site of the
Naumann property and also walked
up to the Dias property. He
testified that the Dias’ pool was empty caked with dirt on the
floor and in his view at that
stage the house needed a coat of paint.
Moroff & Kuhne were duly appointed as the registered person in
terms of the National
Building Regulations and gave the necessary
undertakings relating to the plans for the Naumann dwelling. The
plans were eventually
approved by the City Council. The project began
on 8 March 2008 with a contractor named Monterama commencing the
excavation. It
began at the bottom on the Barbara Road level and
thereafter moving from the top level down. The excavation on the top
level was
completed by 26 March 2008. The extent of the excavations
was calculated with reference to the contour plans and are depicted
on
Exhibits
S1 and S2
.
The latter shows that the top excavation involved the removal of
606m³, the middle level
347m³
and the bottom level 1699m³. This was the equivalent of 3950
bulk meters.
Exhibit
S1
also shows the lift shaft excavation on the middle level which was
conducted later in July and which formed the second phase of
the
excavation and which entailed the removal of a further 1480m³ of
earth thereby making a total of some 4232m³ of soil
removed in
the excavation on the Naumann property.
[82]
After
the first phase of the excavation the bulk excavation was trimmed by
hand and a trench foundation for the top concrete retaining
wall was
cut. This trimming by hand took place in April, May and June 2008. Mr
Naumann testified that there were rocks all over
the site, many of
which had to be cracked using blasting shots. His evidence regarding
the depth of the excavation adjacent to
the Dias property was not
clear but it would appear to have been 5.3 meters on the Sea Point
side and approximately 3.8 meters
on the Llandudno side. Mr Naumann
explained that the trench for the foundation of the back retaining
wall was dug some 600mm in
from the boundary of the Dias property in
order to avoid having to remove a very large boulder underlying the
boundary with the
Dias property. Mr Naumann testified regarding the
manner in which he dug the foundation and constructed the retaining
wall following
his receipt on 29 April 2008 of an instruction and
drawings from the engineer in this regard. He also testified that he
had requested
Moroff to design all retaining walls in such a manner
so that there would be no buttressing of the proposed structure
against any
of the walls. These walls were also built in accordance
with a bending schedule from Moroff.
[83]
When
Mr Naumann was cross-examined generally about whether these walls
were built in conformance with the plans, instructions and
bending
schedules, his responses were unsatisfactory in several instances. It
became clear that in various respects the walls were
not built in
accordance with the plans and bending schedules. The primary reason
for this appears to be that Mr Naumann did not
consider himself bound
by these documents or the instructions or directions of Moroff but
would make whatever adjustments he considered
appropriate in the
circumstances without obtaining fresh plans and/or building approval.
Evidence confidently given by him in chief
on the dimensions of the
wall proved, in cross-examination, to be inaccurate. It also became
apparent that Mr Naumann was very
dependent on the paper trail in the
form of invoices when he reconstructed the program of excavation and
construction and the dimensions
of the building works.
[84]
Having
regard to the chronology of events it would appear that foundations
for the top and lower retaining wall were cast towards
late May with
the foundation for the middle retaining wall, the concrete wall on
the Venter boundary and the first lift of the
bottom retaining wall
around 10 June 2008 with further lifts of these walls being completed
over the remainder of the month and
the bottom retaining wall being
completed around 20 July. None of these dates can however be fixed
with certainty. Mr Naumann
testified that the initial plan was
for the retaining walls to be freestanding since he did not want to
be tied to have to commence
buildings connected to the walls. In this
way he could pause the project at any time without having to build
the house structures
and could focus on his commercial building
projects.
[85]
What
is clear is that as at the date of the major movement after the
commencement of measurements, 26 - 30 July 2008, none of the
three
retaining walls nor the concrete wall on the Venter boundary had been
fully completed. The witness testified regarding subsidence
of an
excavation face during the excavation for the lift shaft around
mid-July 2008 but which he minimised. He also testified that
earlier
on arrival on the site on 9 June 2008 it was found that the
Loffelstein retaining wall on the Dias property had collapsed.
Mr
Naumann then had the Loffelstein bricks broken up and used them as
backfill behind the wall after it was cast. He did not inform
the
Dias’ that their block wall had collapsed or, by definition,
advise them that it was defective for a lack of a foundation.
Nor did
he seek permission from them to use a large part of their collapsed
wall as backfill.
[86]
Mr
Naumann testified that he first learned of ground movement on the
Venter property in mid-July when told thereof by a representative
of
Nick Moroff and he went to do an inspection. After receiving Mrs
Dias’ telephone call around 23 July 2008 to inform him
about
the damage to the pool on her property he went to inspect it the
following day and saw the crack which had occurred when
the rail
pulled out. Mr Naumann made no mention in his evidence of observing
any other damage to the Dias property in general that
day or to the
pool in particular. There was intense rainfall from 27 – 28
July. He testified further that he had attended
the general meeting
at the Dias house on 1 August 2008 but again gave no evidence as to
any damage which he had seen in the entrance,
lounge or dining room
in line with the first defendant’s case that even before the
subsidence the Dias dwelling had been
cracked and defective. He
explained that on that occasion he had not been conducting an
inspection of the house as such. He later
gave evidence concerning
the foundations of the house on the Dias property but it soon emerged
that he had not personally witnessed
any such investigation and his
evidence was inadmissible.
[87]
Mr
Naumann testified regarding the remedial work which he undertook
following Mr Van Wieringen’s advice in early August. The

grouting on the Dias property was completed in September 2008, ground
anchors were installed at Mr Naumann’s expense and
this was
completed in November 2008. Piles were installed on the middle
platform on his property and a 400mm thick concrete raft
slab was
cast over the piles. In addition a concrete wedge slab was cast
between the middle and the top retaining walls which had
the effect
of buttressing the foundation of the back/top retaining wall.
[88]
Under
cross-examination Mr Naumann conceded that the ground on the Dias
property behind the upper retaining wall had moved laterally
towards
Barbara Road and down the slope and that the ground behind the upper
retaining wall moved in the same direction as the
upper retaining
wall. He conceded too that the upper retaining wall had been built in
order to replace the soil which had been
removed in the excavation.
The backfill which had been urgently brought back onto the Naumann
property on the instructions of Mr
Van Wieringen was to replace the
soil which had been initially excavated. The purpose of the soil
anchors which were installed
was to prevent the slope from moving
laterally any further. The soil anchors went through and were
anchored by the middle retaining
wall and once installed the rear
retaining wall stopped moving. The lift shaft excavation was 13m in
length, 5.5m in width and
9.5m deep. It was excavated up to about 6m
from the Dias property and done without any bracing or support. It
involved blasting
at least one large boulder and many others which
needed to be broken and removed. The shaft was excavated during heavy
rains and
there was one partial collapse.
[89]
Mr
Naumann testified that he acted in essence as an owner/builder in
relation to the Naumann property and that it was not the only
site on
which he was working at the time. The rest of the sites on which he
was working at the time were for paying customers.
That is why the
retaining walls on the Naumann property were designed in such a way
that they could be built and then left i.e.
the Naumann residence
building project did not have to be a continuous one.
[90]
Mr
Naumann appeared to have had little if any communication with the
Dias’ during the excavation and building process. He
did not
inform them when their Loffelstein wall collapsed nor earlier when he
removed a boulder which was partly underneath that
wall. Mr Naumann
testified that the wall collapsed on a Sunday evening after rain.
When it transpired that there was no rain on
that particular day, Mr
Naumann testified that it was an accumulation of rain which had
caused the collapse. He had not informed
the Dias’ that their
wall allegedly did not have a foundation because he ‘
didn’t
think it was a problem’
.
He was aware of ‘
problems
on the Venter property’
but
did not inform the Dias’ of this. Mr Naumann was also cross
examined regarding an exchange of emails between himself and
a Mr
Gouvias representing Moroff and Kuhne in May 2008 regarding serious
concerns raised by Mr Gouvias in regard to what he saw
as the
dangerous situation presented by the exposed and undermined
Loffelstein wall (then still standing) on the Dias property.
[91]
On
22 May 2008, i.e. some two weeks before the Loffelstein wall
collapsed, Mr Gouvias emailed Mr Naumann as follows:
‘
We
are extremely concerned wrt ... the back wall excavation. We feel
that the loose material as well as the terraforce wall which
has been
undermine
(sic)
poses
a clear and immanent
(sic)
danger
to those who are asked to work below, or in the immediate vicinity of
the excavation. All work on site is to cease till such
time as this
earthbank has been made safe. We offer two options to achieve said
safety below.’
There
followed a suggestion that either the earth wall be shored using
stays or alternatively that the contractor (Mr Naumann) cut
the slope
to a safe grade “
after obtaining permission from the
neighbour”’.
[92]
Mr
Naumann’s email response the following day said no more than
the following on this topic: ‘
(t)he
contents of your email are noted. We have been concerned about
building this wall before you even designed this structure!!!’
Mr
Naumann testified that he ignored the concerns raised by Mr Gouvias
because the actual designer, Mr Kuhne, was not involved in
the
warning and secondly, because Mr Gouvias was a ‘
junior
associate of that firm. He was neither design engineer nor was he was
the responsible person’
.
[93]
Mrs
Dias was also taken to other email correspondence between Mr Naumann
and Mr Gouvias and in particular, an email from Mr Naumann
to Mr
Gouvias on 14 July 2008 in response to the latter apparently this
time having raised concerns about the lift shaft excavation.
Mr
Naumann’s reply read:
‘
Please
write a letter and tell me that you do not take any responsibility
for the site, that you have warned me of all the dangers
involved and
that it is all my responsibility. In that way you are covered and no
responsibility can devolve on you or your firm.
I am fully aware
of the problems of this site. I have been aware of them since before
the design stage. I cannot help it if there
are such enormous
boulders in the site that the sides collapse. The design if (sic) for
concrete retaining walls – not ground
anchors. I cannot build
the retaining walls before the excavations are done. I cannot shore
it before it is excavated. I cannot
build before it is excavated.’
[94]
This
in turn elicited the following response from Mr Gouvias:
‘
There
is a clause in the ECSA regulations which requires us to take ‘due
care’. This includes dangers on site at any
stage of the
project’s construction. That is all I am trying to exercise. I
feel that the excavation could have been approached
differently, then
again I haven’t had to dig a hole this big before. It may be
that you in full control of what is going
on, but I think it would be
best for you to speak to a specialist geotechnical engineer such as
Mike Van Wieringen to limit your
exposure’
.
[95]
As
Mr Naumann’s cross-examination proceeded it emerged that the
retaining walls had not been built in accordance with the
approved
plans or even the engineer’s instructions. Mr Naumann explained
that he had negotiated a fixed price with the engineers
for the
design of the house, its foundations and retaining walls and, in
order to cut down on expenses, had agreed with them that
they would
not have to do new drawings for the changes which inevitably would be
required. Mr Naumann gave this explanation for
why he did not build
in accordance with the engineer’s drawings. However, in due
course it emerged that the rear retaining
wall was also not built in
accordance with the approved building plans nor with the bending
schedules.
[96]
Mr
Naumann also testified that at a stage in the process prior to the
excavations, he had been prepared to build something not on
the
approved plan and that he had intended to submit plans with a portion
of that which would have been built not being reflected
since
otherwise the Council would not have approved the plans. In the
result, for other reasons, he ultimately did not do this.
What became
clear from this evidence was that as the owner/builder and as someone
with considerable experience in the construction
industry, Mr Naumann
constructed retaining walls that were neither in accordance with the
engineer’s drawings, specifications
or building schedules and,
where it suited him, he ignored the advice and clear warnings of his
engineers. Very little of Mr Naumann’s
evidence, as opposed to
the summary of his expert opinion, was devoted to the alleged defects
in the design and construction of
the Dias dwelling.
[97]
First
defendant’s counsel argued that Mr Naumann was a forthright,
honest and reliable witness the content of whose evidence
and who
demeanour could not be faulted. I cannot fully agree with this
evaluation which overlooks the witness’ shortcomings.
The
details of how the built project deviated from plans only came to the
fore under persistent cross-examination and much of what
was promised
ahead of Mr Naumann’s evidence, such as all the defects in the
Dias dwelling, did not materialize. His recollection
of events around
2008 was not very clear and based largely on the paper trail of
invoices relating to sub-contractors. It appears
that Mr Naumann was
reluctant to defer to anyone when it came to his building project and
believed that he knew best what to do.
His attitude towards his own
consulting engineers and towards the Dias’ was high-handed if
not arrogant. Mr Naumann
is clearly ‘
a
man of action’
and does not easily brook opposition to his chosen path even if this
requires bending the rules in order to obtain the result he
wants. To
his considerable credit, however, when the potentially catastrophic
dimensions of the subsidence became clear he acted
immediately in
implementing the remedial measures which prevented the situation
becoming much worse.
Dr
Peter Day
[98]
Dr
Day, the first defendant’s expert witness, is a civil engineer
with 38 years’ experience specialising in geo-technical

engineering who is employed as a consultant and is also an adjunct
professor of geo-technical engineering at the University of

Stellenbosch. He is a locally and internationally recognised
specialist geo-technical engineer with a particular speciality in
the
field of lateral support. Dr Day is the author of many published
articles of a specialist nature, also in the field of excavation
and
lateral support, the recipient of various professional awards and has
served in several positions of responsibility within
his profession.
Dr Day’s curriculum vitae is particularly impressive and his
reports were comprehensive and meticulously
prepared. He is also a
co-author of the Lateral Support Code, recognised as a normative
bench mark in South Africa.
[99]
In
the initial summary of his opinion, which he confirmed in his
evidence, Dr Day expressed the view that the damaged portions of
the
Dias property were caused by the movement of the unstable hill slope
which in turn was the result of the cumulative effect
of the natural
geo-technical features of the area, the development and loading of
the plaintiff’s property and other properties
on the slope as
well as a number of excavations into the slope dating back to the
early 1980’s. Dr Day stated that the movement
of the slope at
the end of July 2008 was triggered by the excavation at the toe of
the slope on the Naumann and Venter properties
combined with
surcharging of the top of the slope on the Dias and Babrow
properties.
[100]
He
expressed the view that the instability of the slope was not a
consequence of the removal of lateral support on the Dias property

but a result of general instability of the hill slope. His opinion
was further that any failure or ground movement arising solely
from
the removal of lateral support would have had only a localised
effect. He reasoned that since no failure of the ground was
observed
in the area immediately behind the retaining walls this confirmed
that the cause of the observed ground movement was the
result of
general instability of the slope rather than the removal of lateral
support. He added that prior to the commencement
of the excavation on
the Naumann property, the plaintiff and surrounding property owners
contributed to the instability of the
slope over several decades by
the construction of structures thereon which altered the natural
state of the land. He stated that
from a geo-technical perspective
there were a multiplicity of causes of the mobilisation and
subsidence of the scree slope and
that the evaluation and extent of
the degree of the other contributing factors involves ‘
complex,
factual and geo-technical considerations’
.
He observed that since the installation of ground anchors and piles
on the Naumann property, movement of the slope in the direction
of
the Naumann property had effectively ceased.
[101]
In
his October 2015 report entitled
‘
Reasons
for opinion on slope instability’
,
a comprehensive 43 page document with annexures comprising maps,
diagrams and photographs, Dr Day incorporated a section which
sought
to deal with a critical issue in this matter under the heading
‘
Slope
Failure or removal of lateral support?’
.
Here he crisply restated his opinion as follows:
‘…
the
ground movement was not caused by the removal of lateral support. It
was the result of a reduction of load at the lower end
of the slope
leading to a failure of the slope in which the excavation was formed
rather than a failure of the excavation itself.
Furthermore it was
not simply the reduction in load occasioned by the excavation on the
Naumann property that caused the movement
it was the cumulative
effect of numerous excavations along the eastern side of Barbara Road
dating back to the 1980s’.
[102]
By
way of further explanation he stated as follows:
‘
On
a natural slope in undisturbed ground, the weight of the soil at the
top of the slope is a disturbing force i.e. one which promotes

downward and outward movement on an underlying potential failure
surface. The disturbing force is resisted by the weight of the
soil
at the toe of the slope and by the shearing resistance of the soil
along the failure plane. For a slope to remain stable,
the nett
effect of the resisting forces must be greater than the nett effect
of the disturbing forces … The formation of
an excavation at
the toe of the slope has two effects. Firstly, it reduces the weight
of the soil at the toe. Secondly, in the
case of soil that derives
part of its strength from friction, it reduces the shearing
resistance of the soil over the part of the
failure plane below the
excavated area. If the stability of the slope prior to excavation was
already marginal, the formation of
the excavation could cause failure
of the slope. Note that it is not the excavation itself that fails,
but the slope in which the
excavation has been formed. It is thus a
slope failure, not removal of lateral support.
At the time of
the slope mobilisation at the end of July 2008, the excavation on the
Naumann property was substantially complete.
Most of the retaining
walls had been completed and were fully or partially backfilled.
These retaining walls were constructed in
accordance with the design
prepared by the Engineer. Neither the excavations themselves nor the
retaining walls failed. The lateral
support afforded to the
neighbour’s property was therefore not compromised. What took
place was an overall failure of the
slope that encompassed the
excavation, the retaining walls and the front garden of the
neighbour’s property. Even after the
slope mobilised the
retaining walls continued to support the ground behind them including
the portion of the neighbour’s
land that fell inside the
failure zone.’
[103]
A
supplementary expert summary was filed on behalf of Dr Day in
November 2016, the purpose of which was for him to explain the
difference between the mechanisms of failure arising from the removal
of lateral support and mechanisms of failure arising from
slope
instability which in his view are ‘
materially
different’
.
It reads in part:
‘
Removal
of lateral support
Removal of
lateral support is associated with the formation of an excavation
with vertical or near vertical sides, thereby locally
reducing the
lateral (horizontal) stresses in the ground behind the excavation
face. Where necessary, the lateral support so removed
is substituted
by a retaining structure. Retaining structures typically include
concrete retaining walls, soil nails or ground
anchors. If these
structures do not adequately compensate for lateral support removed
by the excavation, the retained soil behind
the excavation face may
undergo lateral and vertical movement and slump into the excavation’.
[104]
Dr
Day then refers to a diagram depicting what he describes as a removal
of lateral support and then sets out the ‘
principal
characteristics of removal of lateral support’
which he describes as follows:
‘
4.1
a potential failure surface develops immediately behind the
excavation face …
4.2
if the retaining structure lacks sufficient stiffness to resist
movements of the ground,
settlement and movement of the retained
ground is localised …
4.3
if the retaining structure fails or moves excessively, the ground
between the wall and the
potential failure surface may slump into the
excavation.
4.4
little or no movement of the ground occurs below excavation level.
4.5
the failure mechanism can be prevented and ground movements reduced
by installing retaining
walls, soil nails or ground anchors or other
forms of lateral support to restore (partially or completely) the
lateral stresses
that existed in the ground prior to excavation.
4.6
the
primary
cause of both ground movement and failure is a reduction in the
lateral (i.e. horizontal) pressure exerted on the face of the
excavation.
[my
underlining]
Slope Instability
5.
Slope instability is associated with loss of equilibrium of sloping
ground …
movement occurs along a single or multiple failure
surfaces which may be curved (typically concave upwards) or planar.
The area
of slope instability is not localised and confined to an
area of excavation (as in the case of lateral support). Slope
instability
is also not necessarily confined to a particular erf or
erven: it is a geo-technical phenomenon which will pervade a general
area.’
[105]
Dr
Day then refers to an attached diagram reflecting, in his opinion,
the principal characteristics caused by slope instability,
which are:
‘
6.1
bodily (en masse) movement occurs on the ground above the failure
surface;
6.2
the movement may be rotational or translational in nature, or a
combination of the two;
6.3
the position and shape of the failure surface depends on a number of
factors including the
nature of the ground …, the geometry of
the slope … the position of the water table;
6.4
with a rotational failure, a scarp may develop at the top of the
failing mass and bulging
may occur at the toe.
6.5
the strength or stability of any retaining structure contained within
the failing mass is
of no consequence to the overall stability of the
slope, as any force exerted by such retaining structure are internal
forces within
the failing mass. Thus even if stressed anchors were
installed to completely restore the lateral stresses in ground an
excavation
face, these would not improve the stability of an unstable
slope unless the anchors extended beyond the failure surface into the

stable ground below;
6.6
the primary cause of the instability is a lack of equilibrium between
the forces acting
on a failure plane and the forces exerted by the
ground above the failure plane including any load supported on such
ground. This
lack of equilibrium can be due to many influences
including changes in soil properties (e.g. due to rainfall), a rise
in the water
table, changes in slope geometry, seismicity and
external loading.’
[106]
In
his evidence Dr Day confirmed the contents of his main and
supplementary reports. He testified that when an excavation was
formed
the removal of the soil from the excavation removes both the
weight of the soil from the base of the excavation but also the
lateral
pressure which that soil exerts or exerted on the surrounding
soil. However, he voiced the opinion that lateral support is that

which you have to do to preserve the stability of that face in the
light of having removed that lateral pressure. He illustrated
what he
saw as the difference between the failure of lateral support and
slope instability by way of a physical model which is
depicted in the
photographs at
Exhibits
V1 – V4.
When block 1, representing the excavation, was removed it could
either provoke a localised failure of a perpendicular excavated
face
(represented by a wedge marked 2 which, as is depicted in
Exhibit
V3
,
has moved both laterally and downwards) or a slip circle failure with
the excavated face itself not failing locally as depicted
in
Exhibit
V2 and V4
.
[107]
It
would appear that Dr Day’s distinction between a failure of
lateral support and a slope instability failure is one which
he
personally draws since he referred to no authoritative definition
upon which he relied. Dr Day was not able to refer the Court
to any
definition in this regard. In answer to a question from the Court, Dr
Day stated that the Code of Lateral Support contained
no definition
of that concept, although ‘
that
was the first place he looked (record page 2968)’
.
In answer to a further hypothetical question from the Court as to
what would be the cause of failure where a slip circle failure
occurs
solely as a result of the depth of an excavation but where there is
no failure of an excavation face, Dr Day stated that
in his view the
proximate cause of such a failure would be slope instability rather
than the removal of lateral support. He clarified
his response when
he testified that in his opinion no matter how deep an excavation is
which precipitates a slope failure or slope
instability, unless there
is a failure of an excavation face (whether through a slip circle or
otherwise) that is not a failure
of lateral support. In this regard
he stated further that:
‘
The
qualifying thing is that the failure of lateral support gives rise to
movements local to the wall whereas slope instability
is something
which encompasses something far greater. It is not within the control
of the person who is excavating and providing
support to his faces.’
[108]
He
described slope instability as ‘
virtually
a force majeure’
situation.
[109]
On
another occasion Dr Day was asked whose definition was it that the
failure of lateral support must manifest in a failure on the
same
level as the retaining wall and, further, whether that was an
engineering definition or a legal definition. Dr Day’s
answer
was oblique, namely that he did not know whose definition it was but
that ‘
we
do from monitoring of new excavations know the extent of movements
which is occasioned by the insufficient lateral support having
been
applied’
(record
page 2775).
[110]
Pressed
further, Dr Day qualified his earlier view by stating that he did not
see the slip circle as ‘
an
act of God, it is accumulation of a series of factors and to hold one
person, who happened to be the last person who performed
that
excavation, solely responsible for the stability of the entire slope
does not make any sense to me whatsoever’
.
He added:  ‘
It
cannot be denied that the excavations which took place were part of
the cause of this failure. A critical question is whether
or not this
was a slope failure of an already compromised slope or a removal of
lateral support. That is the issue’
.
Earlier he had stated that although the slope had ‘
previously
moved’
and was ‘
compromised’
he did not know whether it was brought to ‘
the
point of failure’
.
[111]
A
little further on in response to the Court’s observations that
the slip circle had an element of lateral movement in it,
Dr Day
responded: ‘
(t)here
is no doubt there is a lateral movement, that is entirely correct,
but was the cause of that lateral movement removal of
lateral support
or the removal of weight from the toe of the excavation. That is the
issue. And in my mind the excavation faces
from which lateral support
was removed by removal of the ground did not fail and the retaining
walls had been constructed. The
primary cause or the proximate cause
of the slope movement was the removal of weight from the toe. I think
that that summarises
the entire argument in one sentence’.
He
added that there was ‘
definitely
removal of lateral support by the formation of the excavations. That
is inevitable. The question is whether or not it
was that removal of
lateral support which caused the failure or whether it was the
removal of weight of material from the toe of
the slope’
.
The
law regarding the duty of lateral support
[112]
Only
limited common ground could be found between the parties regarding
the scope of our law of lateral support. The points of difference

extended to the proper interpretation of leading cases on the subject
and included the questions of whether the South African law
of
lateral support is the same as the English law and the effect of the
judgment in
Anglo
Operations
[2]
on previous judgments of our Courts.
[113]
The
main content of these differences concerned the question of whether
the right to lateral support is owed only to land in its
natural
state and, secondly, if this be the case, what is meant by ‘
natural
state’
.
[114]
I
shall firstly set out the positions adopted by the parties. The
plaintiff contended that the duty of lateral support is not limited

to land in its natural state, this being a limitation based on the
erroneous assumption that our law is the same as  English
law.
In the event, however, that the duty is owed only to land in its
natural state, a claim for damages in respect of buildings
will still
lie where such artificial structures impose no additional burden on
the neighbouring land. In that event the onus of
proof in lies on the
party alleging that the land was no longer in its natural state.
[115]
In
a supplementary note the plaintiff advanced a new argument, based on
Regal
v African Superslate (Pty) Ltd
[3]
where it was held that although certain principles may coincide, the
English law of nuisance is not our law. The plaintiff argued
that the
principles applicable in determining the scope of the duty of support
in our law are reasonableness, that liability flows
from the control
of land which ownership brings and that it is a landowner’s
duty to prevent damage to his neighbour. Applying
these principles to
the present matter, it was submitted, the first defendant had,
through her unreasonable excavations, removed
the lateral support her
property owed to the plaintiff’s property and was thus strictly
liable for the damages suffered by
the plaintiff.
[116]
The
first defendant’s counsel described the duty of lateral support
in our law as a case by case rule of neighbour law transplanted
from
English law and strongly influenced by English law principles. The
duty of lateral support is owed only to contiguous land
and extends
no further than to maintain such land as if it were in its natural
state. As a consequence of these limitations the
duty cannot be
construed as imposing a duty to stabilise a slope on which a number
of properties are situated. The first defendant
submitted further
that the authorities are clear that the right to lateral support
relates only to undeveloped land. The first
defendant did concede
that liability for damage to artificial structures on land could
follow when the injured party discharged
the onus of establishing
that the subsidence would have occurred even if such structures had
not been present on the land. The
first defendant submitted further
that the new argument advanced by the plaintiff based on
Regal
was
without substance, particularly insofar as it countenanced that the
duty of support was not limited to land in its natural state
and that
certain principles said to be extracted from
Regal
(such as reasonableness) applied to actions based on the right to
lateral support.
[117]
The
first third party laid emphasis on the right to lateral support being
based on strict liability which, it contended, required
the remedy to
be limited to instances where direct causation was proved and where
there was an actual or literal loss of support.
It contended further
that the duty of lateral support clearly lay in respect of
undeveloped land but seemed to suggest that where
the land is
developed the existence of the duty would depend on an evaluation of
the ‘
practical
realities’
pertaining, presumably, to the properties in question and what gave
rise to the alleged breach.
[118]
In
view of the uncertainty regarding the present state of our law on
this subject I propose to firstly consider the two leading
cases and
thereafter the views of academic writers.
[119]
London
and SA Exploration Company v Rouliot
[4]
concerned
the right of an owner of land to lateral support to adjacent land but
within the context of mining operations. It was
held by the Court,
comprising De Villiers CJ, Smith J and Buchanan J, that the right of
an owner to lateral support from adjacent
land was recognised by the
law of the Cape Colony. De Villiers CJ remarked that it was an
extraordinary circumstance that there
should be a dearth of authority
in the ‘
Dutch
law-books’
upon the question of lateral support probably, he surmised, because
the question had never been of practical importance ‘
seeing
that there are no mines in Holland and a necessity for deep
excavations must seldom have arisen’
.
[5]
The learned Chief Justice held that in ‘
the
absence of direct authority, this Court may well be guided by
well-established principles of the Roman law and of modern systems
of
law, provided that they do not lead us to conclusions inconsistent
with the Dutch law’
.
[6]
[120]
Anglo
Operations Ltd v Sandhurst Estates (Pty) Ltd
[7]
was
a mining case concerning the competing rights of the holder of
mineral rights and the rights of the surface owner and, in
particular,
whether the mineral rights holder was entitled to divert
a stream to facilitate open cast mining activities.
[121]
The
Court held that the principle of lateral support established in
Rouliot’s
case was important only as a principle of neighbour law and that it
applied to lateral support between neighbouring land owners
only.
[8]
It held further that the relationship between a land owner and the
holder of mineral rights in respect of the same property is
regulated
by the principles of servitudes and not by the principle of lateral
support.
[122]
There
appears to be general agreement that there is a degree of confusion
and lack of clarity on the origin of the right of lateral
support in
our law which originates from uncertainty and dissent about
historical origins of the principles. To a certain extent
this lack
of clarity was resolved by the Supreme Court of Appeal in
Anglo
Operations
when
it decided that it was not important to decide whether the law
regarding lateral support originated in Roman, Roman Dutch or
English
law because a right of lateral support had been adopted in early case
law as part of South African law.
[123]
In
Anglo
Operations,
Brand JA on behalf of the Court said the following of the decision in
Rouliot
:
‘
The
gravamen of the decision in this case was that a rule, similar in
content to the English rule of lateral support, which provides

landowners, as an intrinsic element of their ownership, with the
right of adjacent support of their land, should be incorporated
into
our law.’
[9]
[124]
The
Court also had to deal with the case of
Coronation
Collieries v Malan,
[10]
in which the central question was whether an underground miner owed
the landowner a duty of vertical or subjacent support of the
surface.
In this regard Brand JA stated:
‘
Unlike
the Court a quo I do not believe that the question regarding the
continued recognition of the principle of lateral support
is one that
we have to concern ourselves with in this case. It is clear that the
principle was adopted in Rouliot as a rule of
neighbour law. The real
question in this case is whether that principle of neighbour law
should have been extended, as was done
in the Coronation Collieries
case, to govern the relationship between mineral rights holders and
the owners of the same land.’
[11]
[125]
Referring
again to the decision in
Rouliot,
Brand JA stated:
‘
Equally
erroneous, in my view, is the statement that De Villiers CJ decided
to incorporate the English doctrine of lateral and subjacent
support,
with all its ramifications, into our law. On the contrary, I agree
with the statement by the Court a quo (at 366B) that
what had
happened in Rouliot was that:
“
De
Villiers CJ and Smith J simply introduced, as Judge-made law, a rule
which they regarded as common to all civilised systems of
law
because, as they perceived it, a lacuna existed. The Judges did not
concern themselves with the exact pedigree of the rule.
. . . The
rule was introduced because it was regarded as just and
equitable.”
[12]
[126]
The
importance of
Rouliot
and
Anglo
Operations
together, would appear to lie, firstly, in the recognition that the
principle of lateral support is a rule of neighbour law, introduced

because it was regarded as just and equitable, and secondly, that it
is not simply a carbon copy of the English law of lateral
support.
[127]
Widely
diverging claims were made by the parties in the present matter
regarding the effects of the decision in
Anglo
Operations
on the principle of lateral support in non-mining cases. On behalf of
the plaintiff, it was contended that the decision in
Anglo
Operations
has
put paid to the mistaken notion that our law of lateral support is
the same as English law and that the right of lateral support
applies
only to land in its natural state, most notably expressed in
East
London Municipality v South African Railways and Harbours
.
[13]
[128]
By
contrast the first defendant’s counsel contended that the
implications of the finding in
Anglo
Operations
that ‘
the
principle of lateral support formed no part of Roman Dutch Law’
are
that all prior decisions in which our courts sought to determine the
contents of the rule of lateral support with reference
to Roman Dutch
law were mistaken and now represent bad law and, secondly, that all
the cases following on
Rouliot
which
determined the content of the lateral support rule with reference to
English law were correct in doing so.
[129]
In
my view neither of these propositions is entirely correct. In the
first place
Anglo
Operations
did not reject the gravamen of the decision in
Rouliot
which was that ‘
a
rule,
similar
in content
to the English rule of lateral support, which provides land owners …
with a right of adjacent support of their land, should
be
incorporated into our law’
[my
underlining]. Thus the influence of the English law of lateral
support was explicitly recognised. However,
Anglo
Operations
held that it was erroneous to suppose that ‘
De
Villiers CJ decided to incorporate the English doctrine of lateral
and subjacent support, with all its ramifications, into our
law’
.
Furthermore, the Court in
Anglo
Operations
approved the dictum by the lower court that
Rouliot
simply introduced, as judge-made law, a rule which they regarded as
common to all civilised systems of law because, as they perceived
it,
a lacuna existed and that the judges in
Rouliot
did not concern themselves with the exact pedigree of the rule, the
rule being introduced because it was regarded as just and equitable.

In my view in
Anglo
Operations,
the Supreme Court of Appeal did not purport to state that our law of
lateral support as between neighbours was exactly the same
as that as
the English law nor did it claim that the provisions of English law
are inapplicable. There was no need for the Court
to do so since that
question was not before it, the issue which it decided being the
question of subjacent support as between mineral
rights holders and
land owners in relation to the same piece of land.
[130]
Thus
the decision in
Anglo
Operations
does not directly shed any further light on one of the central issues
in the present matter which is whether the duty of lateral
support
between contiguous pieces of land extends to buildings on that land
or only the land in its natural state and, if the latter,
the scope
of any exceptions to this rule.
[131]
As
Professor Milton has pointed out, although the right of lateral
support to land was accepted without any question by the courts
after
Rouliot’s
case, there has been considerable disagreement as to whether that
right extends to land with buildings on it.
[14]
[132]
In
Johannesburg
Board of Executors and Trust Company Ltd v Victoria Building Company
Ltd,
[15]
Morice J held that the right of support in our law was owed both to
land and to buildings and Chief Justice Kotze concurred in
this
stating ‘
it
is fair and just that such should be the law’
.
[16]
[133]
The
principle established in the
Victoria
case
was approved of by the Cape Courts in
Phillips,
[17]
where De Villiers AJ held that ‘
the
Roman Dutch law recognises a right of lateral support for land and
buildings as between adjoining tenements’
.
Similarly in Natal the principle was upheld in
Grieves
v Anderson, Grieves v Sherwood
.
[18]
[134]
However,
in 1951 in
East
London Municipality v South African Railways and Harbours,
[19]
Reynolds J unequivocally rejected the principle established in the
Victoria
case
and held that the right of lateral support extends only to land in
its natural state and not to constructions such as buildings
upon it.
The Court concluded that –
‘
As
regards artificial constructions on land our law is the same as the
law of England ….
By
the Law of England it is clear that this right of support of land to
land is only given and limited to such amount of support
as is
required by the supported land in its natural state’.
[20]
[135]
The
approach adopted in
East
London Municipality
was unquestioningly followed by the Natal Courts in
Demont
v Akals’ Investments (Pty) Ltd and Another
.
[21]
There it was held that:
‘
An
owner of land is normally entitled to expect and to require from land
contiguous to his own such lateral support as would suffice
to
maintain his land in a condition of stability if it were in its
natural state. A landowner can, of course, alter the condition
of his
land, for example by excavating or building on it, but he cannot
normally, by the mere fact of doing that, acquire greater
or
different rights to lateral support.’
[22]
Similarly
in
Gordon
v Durban City Council,
[23]
the view taken by Reynolds J in
East
London Municipality
was endorsed.
[136]
These
decisions were criticised by plaintiff’s counsel who pointed
out that in
Demont’s
case, Selke J’s formulation of our law relating to the duty of
lateral support was made without reference to any authority
and
appears to have been drawn from an uncritical acceptance of Reynolds
J’s judgment in
East
London Municipality
.
In
Gordon’s
case, the statement of our law in the
East
London Municipality
case was followed without the Court considering whether it was
correct or not. Even in the latter case, counsel contended, the
Court
found for the plaintiff notwithstanding that there was a building on
its land, concluding that ‘
the
weight of the plaintiff’s building made no appreciable
difference’
.
[137]
Nonetheless,
the statement by Professor Van der Walt, that ‘
(d)espite
the early disputes about its origin, it was therefore generally
accepted by 1980 that the right of lateral support forms
part of
modern South African law and that it is essentially similar to
English law, except for specific points where it had developed

further locally, particularly in cases about mining’
appears
correct.
[24]
Noting that the
decision in
Anglo
Operations
established a distinguishing principle in terms of which the
operation of the right to lateral support is restricted within the

sphere of neighbour law, he analysed the implications of the
Anglo
Operations’
principle inter alia in regard to non-mining cases. He notes that
although it is usually said that the right of lateral support
applies
to land in its natural state and not to buildings ‘
this
aspect has been dealt with inconsistently in the non-mining cases
involving excavation on one property that caused withdrawal
of
lateral support from the neighbouring property and resulted in
subsidence of the soil’.
[25]
Professor van der Walt identifies the decision in
East
London Municipality
as being the leading case within the sphere of non-mining cases to
deviate from or reject the early decisions of our courts which

recognise a right of lateral support for land and for buildings, the
prime exemplar thereof being the
Victoria
case.
[26]
He makes the point that there is a difference of opinion regarding
the proper direction of our law in this regard, inter alia,
in his
reference to Professor Milton’s view that it was wrong to
restrict the right of lateral support to land in its natural

state.
[27]
[138]
In
East
London Municipality,
Reynolds J first recognised the right of support of land to land in
our law with the general statement that ‘
our
law is the same as the law of England as regards the right of support
of land to land and seems to rest on the principle that
it is not so
much a principle as a right given in the nature of things’
.
[28]
Later he dealt with the contention that our law differed from the
English law inasmuch as lateral support is not restricted to
land in
its natural state but extends to buildings. He noted that the main
authority for this proposition rested on the strength
of the decision
in
Victoria.
He
analysed that decision finding that the references to the Roman law
in that case did not support the view which Morice J expressed
and
then stated:
[29]
‘
Moreover
on principle it is difficult to see how a right of support for all
buildings, even those increasing the natural burden
of support, can
apply. The right of support of land to land in its natural state
rests on principles common to all systems of jurisprudence
…
(h)ence on principle there can be no right of support for artificial
constructions which did not in nature exist.’
And
concluded:
‘
I
therefore find myself in agreement … that as regards
artificial constructions on land our law is the same as the law of

England …’
[139]
Reynolds
J then went on to state that English law is clear ‘
that
this right of support of land to land is only given and limited to
such amount of support as is required by the supported land
in its
natural state’
and later that the ‘
natural
state’
of land ‘
must
surely mean that the land to be supported is in such a state at the
time of the withdrawal of support that no extra burden
artificially
there (i.e. not placed there by nature) increases the amount of
support it then requires beyond the amount it will
require if that
artificial burden were not there so as itself to cause subsidence
which would not otherwise have occurred if the
land was without that
burden’
.
[30]
The learned judge then reviewed the English authorities, finding them
in support of this view.
[140]
It
is notable however that Reynolds J’s analysis of the law and
his finding that our law was the same as that as English law
was
obiter
inasmuch as the circumstances of that case did not concern land upon
which buildings had been placed. Rather, it involved the grant
of a
public road and the laying of cables along that road in circumstances
where, as the learned Judge pointed out:
‘
The
matter was not raised by either side in the pleadings that the cables
imposed any extra burden or weight that occasioned the
subsidence.
There was no evidence led on this point and advisedly so for the
evidence of the geologists, etc., indicated any possible
extra burden
had nothing to do with the subsidence.’
[31]
[141]
The
plaintiff’s counsel also argued that Reynolds J reached his
conclusion after himself relying on the
Rouliot
case but in circumstances where the Supreme Court of Appeal in
Anglo
Operations
,
having reference to the same case, reached a different conclusion.
The point is well made. The Court in
Rouliot
found that the right of an owner of land to lateral support from
adjacent land was recognised by the law of the Cape Colony. This
it
did ‘
in
the absence of direct authority’
and ‘
guided
by well-established principles of the Roman law and of modern systems
of law, provided they do not lead us to conclusions
inconsistent with
the Dutch law’
.
The Court nowhere found that our law on this subject was the
same
as the law of England. In
Anglo
Operations
,
as certain key passages referring to
Rouliot
(quoted in paragraphs 123 – 125 above) make quite clear: the
doctrine of lateral support was introduced as judge-made law
because
it was just and equitable, was adopted as a rule of neighbour law and
was not a slavish importation of the English law
into our system.
[142]
In
these circumstances, it would appear to me, there is no authoritative
or binding decision in our law that limits a land owner’s
right
of lateral support to the land in its natural state only, as is the
case in English law. There are, furthermore, cases, most
notably
Victoria
,
where it was held that the right extended to support to buildings on
the land. What is more our law in regard to the right of
lateral
support is squarely located within the law of neighbours in which one
of the guiding principles is that of reasonableness.
[143]
The
arguments in favour of the duty of lateral support extending to
buildings or artificial constructions on land were comprehensively

set out by Professor Milton.
[32]
He pointed out that, as was recognised by Lord Penzance in
Dalton
v Angus
,
[33]
the English rule works obvious injustice.
[34]
Professor Milton thus posed the central question as being whether
South African law will accept this same (English) tradition of
high
regard for the rights of an owner to full enjoyment of his land,
including the right to cause a neighbour’s house to
collapse
with impunity, or whether it will adopt the more just and equitable
rule (he submitted) that a right of support is owed
to buildings.
Professor Milton argues that the exception whereby the English law
does not apply to all artificial erections on
land ‘
so
long as the presence of the buildings does not materially affect the
question, or the additional weight did not cause the subsidence
which
followed the withdrawal of support’
was
doubtfully of any real value.
[35]
[144]
In
this regard, Professor Milton stated:
‘
It
is an inevitable tendency of modern life for more and more people to
gravitate to cities. As a result larger buildings must be
erected to
accommodate them and provide employment. The larger the buildings,
the greater the pressure on the soil and the less
the duty of lateral
support owed by neighbouring land. This, it is submitted, is an
illogical and unrealistic approach and, on
principle, it should not
be preserved’
.
[36]
[145]
Turning
to policy considerations, Professor Milton expressed the view that it
was difficult to discover the reason for the rejection
of the
doctrine of the
Victoria
case
and submitted that it was unwarranted. In this regard he stated—
‘
(a)s
has been seen, Roman law had no special rules regarding lateral
support. The matter was approached on general principles of
property
law. Any interference with rights of enjoyment of land, including the
withdrawal of lateral support, would have given
rise to an action
based on Roman law equivalents of nuisance. On this simple basis
there would have been no distinction drawn between
removal of support
of land with or without buildings on it.’
[37]
[146]
He
then goes on to state that the modern doctrine of nuisance is
essentially concerned with the balancing of the conflicting interests

and rights of neighbouring owners of land.
[147]
In
regard to foreign law, Professor Van der Walt notes that in both
Dutch and German law the right of support applies to built up
land as
well as land in its natural state.
[38]
He adds that ‘
restriction
of the right of lateral support to land in its natural state has been
subjected to growing criticism recently, not least
because of the
anomalies it causes’
and that the Court of Appeal of Singapore recently overturned the
classic principle on this point and extended the right of support
to
buildings, relying on the principle of
sic
utere tuo ut alienum non laedas
(‘use your own property so as not to invade the rights of
another’), an innovation that might be followed by other
final
courts of appeal, it was said at the time.
[39]
[148]
Professor
Milton sought to find policy reasons for the rejection of the
doctrine established in the
Victoria
case,
expressing the view that its rejection was unwarranted.
[40]
The first of two factors which he considered as influencing the
direction taken from the mid-20
th
century in our law was that bylaws and building regulations in urban
areas ‘
guarantee’
that buildings will not be rendered dangerous or caused to collapse
by the removal of lateral support of adjoining properties with
the
result these rules have made it ‘
unnecessary’
for the Courts to evolve rules to deal with the removal of lateral
support in such areas.
[41]
[149]
The
second policy reason he identifies is the development of a body of
law regarding mines and mining which has influenced the law
of
lateral support to land and which strikes a compromise between the
rights of enjoyment in land and the interests of the mining

industry.
[42]
Professor Milton
expressed the further view that it was this concern with the
definition of mining rights which caused the law
of lateral support
under normal conditions to be diverted from the course set by the
Victoria
case and finds that there was no justification for applying the
decision in
Douglas
Colliery v Bothma,
[43]
a
mining law case, to the ordinary rules of lateral support as Reynolds
J did in
East
London Municipality
.
He submits, in conclusion, that a clear distinction must be made
between the right of support as existing in private property
law and
as existing in mining law and that in the former case the doctrine of
the
Victoria
case is to be preferred. Professor Milton’s view is
encapsulated in the following passage:
‘
The
English law clearly regards the right to excavate on land as a
superior right to that of erecting buildings up to the limits
of
adjoining proprieties. But in a modern urbanised society with heavily
built up areas this bias in favour of rights to excavate
with
impunity cannot be tolerated. Modern law clearly prefer the right to
erect buildings without fear of their destruction as
being more
important that an unlimited right to excavate on land’
.
[44]
[150]
In
significant respects the views expressed by Professor Milton have
been borne out by the decision of the Supreme Court of Appeal
in
Anglo
Operations
,
particularly in its endorsement of the Court
a
quo
’s
observation that it was incorrect to state that in
Rouliot
‘
De
Villiers CJ decided to incorporate the English doctrine of lateral
and subjacent support, with all its ramifications, into our
law’.
[45]
Instead
the Court agreed with the statement of the Court
a
quo
that what had happened in
Rouliot
was that the Court introduced the doctrine of lateral support as
Judge-made law because a lacuna existed and it regarded this as
just
and equitable. I interpret these dicta in
Anglo
Operations
as rejecting the notion, principally expressed in
East
London Municipality
,
that our law of lateral support in non-mining cases is or must follow
the contours of the English law (and which seems to have
been
accepted as axiomatic in many cases subsequent to
East
London Municipality
).
[151]
What
is more, I find the reasons and views expressed by Professor Milton
on why the doctrine in the
Victoria
case is to be preferred, persuasive. It is significant that,
notwithstanding that the excavations which lie at the heart of this

matter took place in a well-developed and long established suburb in
a major metropolitan centre and where, apparently, all planning

approvals were obtained and all building by-laws and regulations were
observed, a calamitous subsidence took place. It led to the
complete
demolition of two dwellings, the cessation of building activity on
the first defendant’s property ever since and
the necessity for
extensive repairs on the two properties neighbouring those on which
the excavations were formed. From the perspective
of the plaintiff,
the building by-laws and regulations did anything but, to use
Professor Milton’s language, ‘
guarantee
that buildings will not be rendered dangerous or caused to collapse
by the removal of lateral support of adjoining properties’
.
[46]
It must also be borne in mind that the introduction of the duty of
lateral support into our law as Judge-made law clearly implies
that
this law may be developed and adjusted as the demands and exigencies
of modern society may require.
[152]
In
the result, I do not consider myself bound by and respectfully
disagree with the principle enunciated in
East
London Municipality
and prefer the view that the duty of lateral support in relation to
contiguous pieces of land is owed to buildings as well.
[153]
However,
too broad a formulation of the right or duty of lateral support could
lead to conceptual and equitable difficulties, particularly
where the
contiguous parcels of land are situated on a slope. Where a property
has been unduly or unreasonably loaded through the
erection of
disproportionately large or heavy structures, it would seem unfair in
my view that a neighbouring piece of land should
attract an
equivalently onerous duty of lateral support.
[154]
In
a supplementary argument, plaintiff’s counsel argued that the
first defendant’s excavations had constituted unreasonable
use
of her property. In making this argument counsel relied on certain
principles of neighbour law as appear in passages from
Regal.
[47]
In
Regal,
the
then Appellate Division held that the English law of nuisance had not
been substituted for our law and that it was necessary
to investigate
our own common law sources. In arguing for the touchstone of
reasonableness in the present matter, plaintiff’s
counsel
relied inter alia on the following passage from
Regal
:
‘
In
hoofsaak het ons hier te doen met wat buurreg genoem kan word. As
algemene beginsel kan iedereen met sy eiendom doen wat hy wil,
al
strek dit tot nadeel of misnoeë van 'n ander, maar by
aangrensende vasgoed spreek dit haas vanself dat daar minder ruimte

is vir onbeperkte regsuitoefening. Die reg moet 'n reëling
voorsien vir die botsende eiendoms - en genotsbelange van bure,
en hy
doen dit deur eiendomsregte te beperk en aan die eienaars teenoor
mekaar verpligtings op te lê. Sommige van die beperkings

ontstaan direk daaruit dat 'n eienaar se eiendomsregte op sy grense
eindig. (
Dernburg
System 1 par.  162
).
Hoewel dit nie 'n strakke reël is nie, is dit hom gevolglik nie
geoorloof om te doen wat iets op sy buurman se grond laat
kom of 'n
direkte uitwerking daarop het nie.
[48]
And
further:
‘
'n
Oorweging wat meermale teengekom word, is dié van
billikheid.’
[49]
[155]
Bearing
in mind the manner in which the plaintiff pleaded his case, it is not
open to him to mount an alternative case based on
the alleged
unreasonableness of the first defendant’s excavations. That is
not the case which the latter was called upon
to meet. I see no bar
however to the concept of reasonableness playing a role in
determining the scope of the duty of lateral support,
more
particularly in determining whether a duty of lateral support
extending to buildings can be limited where the property damaged
by a
breach of this duty had been unreasonably loaded by artificial
constructions.
[156]
In
the result, I consider that the appropriate approach is to hold that
a duty of lateral support extends not only to land but also
to
buildings, save where such land has been unreasonably loaded so as to
place a disproportionate or unreasonable burden on the
neighbouring
land.
[157]
In
the circumstances of the present case, it is common cause that the
first and second defendants were the owners of land contiguous
to the
plaintiff’s property. In the light of my finding that a duty of
support is owed in these circumstance both to land
and buildings,
both defendants were under a common law duty to provide lateral
support to the plaintiff’s property. This
largely answers the
first of the separated issues save that it does not deal with the
question of whether the plaintiff unreasonably
loaded his property
through the construction of a residential dwelling thereon, a
question which I now address.
[158]
In
my view there is no basis on which to find that the plaintiff
unreasonably loaded his property. The dwelling constructed on the

Dias property, although substantial, was in no way out of keeping
with numerous similar dwellings on the same slope in the same
suburb.
I accept the evidence of Mr Van Gyssen that the dwelling was properly
designed and built. In regard to the terracing of
the property and
the construction of the Loffelstein wall, Dr McStay testified that it
is inherent in the built environment that
the natural ground has been
modified to enable development to take place and, furthermore, that
the Loffelstein wall constituted
perfectly reasonable measures
typical of residential properties in the area and placed no
significant risk on properties downslope.
Similarly, I accept this
evidence. Above all, as the evidence indicates, the Dias dwelling,
garden and wall stood unaffected for
at least 16 years before the
excavations on the Venter and Naumann properties in 2008. The
evidence is that no fill was brought
onto the Dias property when it
was developed; at most some terracing was done using existing fill.
In the circumstances, on my
view of the correct legal approach to the
duty of lateral support, there is no room for a finding that the
plaintiff forfeited
his right to lateral support from his neighbours
by unreasonably loading his land.
The remaining separated
issues:
Did the excavations breach
the duty of lateral support and, if so, did this lead to the slope
mobilisation?
[159]
The
starting point in dealing with these issues is the question of the
condition of the plaintiff’s property, in particular
the
dwelling, prior to the events of 2008. The thrust of the attack from
the first defendant was that the dwelling was poorly constructed,
in
poor condition and cracking prior to the excavations which took place
in 2008. The evidence from the plaintiff and his wife
was, in broad
terms, that they had spared no expense in building their ‘
dream
house’
,
had hired reputable builders, architects and engineers and that the
house had been built to high standards; furthermore, that
prior to
2008, apart from one or two minor faults such as a cracked tile or a
lick of paint being required, the house had been
in impeccable
condition. The evidence of the plaintiff and her husband regarding
the condition of their house prior to 2008 was
detailed and
convincing and was borne out by photographs of the dwelling taken in
those years. This evidence was supported in the
first place by that
of the neighbours. Mr Wentzel made it his business to keep an eye on
the condition of properties in Theresa
Avenue and he noticed no flaws
in the plaintiff’s property. Mr Babrow’s evidence was
even more pointed. He visited
the plaintiff’s property
regularly pre and post 2008 and found it to be in immaculate
condition prior to the excavations.
By contrast after 2008 he had
witnessed the ever growing number of cracks and structural defects in
the house.
[160]
The
plaintiff’s evidence was also supported by that of Mr Van
Gyssen, an engineer who examined the architectural drawings
for the
plaintiff’s dwelling and satisfied himself that it had been
built in accordance with those plans. Mr Van Gyssen had
extensive
experience in the field of residential dwellings and in inspecting
cracked dwellings. He testified that it had been built
by a reputable
master builder and monitored both by the appointed architect and an
engineer. He expressed approval of the structural
design of the
dwelling which was executed in accordance with the plans and he
dismissed suggestions that the many cracks which
manifested in the
house after 2008 were a result of defective design or construction.
He testified that if this had been the case
these defects would have
manifested within a few years after construction of the dwelling. He
further testified that the decision
whether to install expansion
joints in a dwelling rested with the appointed structural engineer
and these were not mandatory. He
expressed the further opinion that
fully framed structures such as the Dias dwelling do not normally
have soft joints.
[161]
The
evidence from the defendants regarding the condition of the
plaintiff’s dwelling prior to 2008 was sketchy at best. Mr

Naumann proffered an expert opinion in the capacity of a qualified
quantity surveyor with extensive experience in the construction

industry. He is not a qualified quantity surveyor, however, and his
view that the plaintiff’s dwelling required soft joints
and
without them would inevitably have cracked within a few years as a
result of movement was contradicted by factual evidence
that the
house was in excellent condition prior to 2008 and by Mr Van Gyssen’s
evidence. Notwithstanding the summary of his
opinion and despite the
fact that he had visited the plaintiff’s dwelling on or about 1
August 2008, Mr Naumann only saw
one (recent) crack in the pool (to
which his attention was drawn by the plaintiff) and could describe no
damage to the rest of
the dwelling. As an experienced builder and
being aware at the time that his excavations were being blamed for
the damage to the
Dias property, it is unlikely that he would have
missed a general deterioration in the condition of the house. One
must also take
into account that, insofar as Mr Naumann proffered an
expert opinion, he could hardly claim to be impartial.
[162]
The
only evidence in support of Mr Naumann was that of Dr Day, a civil
engineer but specialising in geotechnical engineering and

particularly in the field of lateral support. An important and
recurring theme in Dr Day’s evidence was that there had been
a
pre-existing crack in the pool on the plaintiff’s property
which suggested that even prior to the 2008 excavation the dwelling

had been under structural strain. Ultimately however Dr Day had to
abandon his argument that the pool had previously sustained

structural damage when it turned out that the pool had not been
cracked before 2008.
[163]
Having
regard to the evidence as a whole I am satisfied that the plaintiff’s
dwelling was properly designed and constructed
and that prior to 2008
it was in excellent condition, structurally and otherwise.
[164]
The
reverse image of the question addressed above is the extent of the
defects in the plaintiff’s property and when these
manifested
themselves. Both the plaintiff and her husband testified in detail of
the pool beginning to detach itself from the house
which commenced
with the pool rail popping out of the wall and a hairline crack
between the house and the pool on or about 23 July
2008. This had
been preceded by furrows appearing in her lawn and a dip in the lawn
nearby a feature rock. This was the day when
the second defendant
abandoned his property as large cracks appeared in his newly built
garage floor. From this point on extensive
damage began to manifest
in the plaintiff’s dwelling in the form of cracked tiles,
cracks in concrete slabs, shifting doorframes,
cracks in the wall,
windows being twisted out of place and units attached to the walls
pulling away. On the advice of Mr Van Wieringen,
and ever since then,
the plaintiff’s wife marked all these cracks with masking tape
and dated them. Mr Dias confirmed his
wife’s evidence in this
regard in all material respects testifying that his lounge had, at
last count, 100 cracks and his
dining room, 52. An inspection in loco
served to confirm the damage to the dwelling in the form of numerous
cracks some of which
led to water leaks. It is so that the degree of
damage has been accentuated by the fact that, on the advice of Mr Van
Wieringen,
the plaintiff has not had any remedial or repair work done
to the house since 2008. Even taking this factor into account,
however,
the extent and severity of the accumulated damage is plain
to see. The evidence of this damage and when it began to appear was
overwhelming and uncontroverted. Whatever the precise nature of the
geological event in and around July/August 2008, I find that
on the
evidence and on the probabilities it was responsible for the damages
which manifested in the plaintiff’s house.
[165]
A
great deal of evidence was heard, mainly that of the experts,
concerning the nature and mechanism of the geological event which

took place over the period of July and August 2008. Dr Day expressed
the opinion that the inferred mechanism indicated a ‘
rotation
slip failure along a dish shaped failure surface with downward
movement over the upper portions of the slope and heave
at the toe’
.
Dr McStay concluded that the ground movements and structural damage
experienced at the plaintiff’s property were the result
of a
progressive series of slope failures forming what are termed ‘
en
echelon slip planes’
i.e.
a complex series of roughly circular failure planes. As both experts
recognised, the exact nature of the slip circle failure
could not be
determined with certainty since it could only be inferred rather than
physically observed. In my view it is unnecessary
to determine which
of these theories is to be preferred since in my understanding they
are but variations of the same mechanism.
[166]
The
real difference between the two main expert witness and the key issue
in this matter concerned the question of whether the slip
circle
failure was due to a failure of lateral support or not. Dr McStay’s
initial opinion was that the ground movement represented
the
triggering of a slope failure due to the removal of lateral support
by the excavation of a large mass of soil and boulders
on the
properties of the first and second defendants. Dr McStay considered
possible causes and factors contributing towards the
ground movements
such as poor soil conditions, groundwater seepage, heavy rainfall and
previous construction work on the overall
slope. He expressed the
view nonetheless that the conditions affecting the stability of the
plaintiff’s property were not
unforeseen and could reasonably
be anticipated given the location, prevailing physical environment
and winter rainfall.
[167]
In
a supplementary report Dr McStay concluded that the excavations
carried out on the second defendant’s property during 2008

played a minimal, if any, role in the removal of the lateral support
previously afforded to the plaintiff’s property. Dr
McStay
explained this deviation from his original opinion on the basis that
he had initially been unaware that excavations on the
second
defendant’s property had been completed by 2 April 2008, that
thereafter considerable ground was excavated from the
first
defendant’s property and, all in all, because the excavations
from the Venter property were approximately one tenth
of those on the
Naumann property which was immediately adjacent to the Dias property.
[168]
Dr
Day’s opinion throughout was that the damage to the Dias
property was caused by the movement of the unstable hillslope
on
which it was situated and that instability in turn was the result of
the cumulative effect of the ‘
natural
geotechnical features’
of
the area, the development and loading of the Dias property and other
properties in the area on the affected slope and a number
of
excavations into the slope dating back to the early 1980’s. In
his view the movement of the slope towards the end of July
2008 was
triggered by the excavation of ground at the toe of the slope on the
first and second defendant’s properties ‘
combined
with surcharging of the top of the slope by the placement of fill
material’
on the Dias and Babrow properties. His opinion was further that the
instability of the hillslope was not a consequence of the removal
of
lateral support to the Dias property but of general instability of
the hillslope. In his view any failure or ground movement
arising
solely from the removal of lateral support would only have had a
localised effect i.e. it would have been confined to the
areas
immediately behind the retaining walls built on the Naumann property.
Since no failure of the ground was observed in such
areas, this
confirmed that the cause of the general observed movement was the
result of general instability of the slope rather
than the removal of
lateral support.
[169]
Dr
Day added that prior to the excavation on the Naumann property the
plaintiff and surrounding property owners had contributed
to the
instability of the slope over several decades by the construction of
structures and the loading of surrounding properties,
in most
instances accompanied by terracing of the sites, all of which
activities altered the ‘
natural
state of the land’
.
[170]
Before
considering in greater detail the views of the respective experts on
whether there was a failure of lateral support or not,
it is
appropriate to have further regard to some of the principles
applicable when courts consider the evidence of expert witnesses.

Firstly, it is trite that the opinion of expert witnesses is
admissible only where, by reason of their special knowledge and
skill,
they are better qualified to draw inferences than the judicial
officer. Secondly, expert/opinion evidence is admissible when it
can
appreciably assist the Court.
[50]
Thirdly, the opinions of expert witnesses are admissible only where,
by reason of their special knowledge and skill they
are better
qualified to draw inferences than the judicial officer.
[51]
In this regard an expert witness should not usurp the function of the
Court.
[171]
It
is for the Court to determine whether the topic demands expert
evidence. The Court does not defer to scientific opinion as to

whether expert evidence is required or permissible.
[52]
[172]
An
expert witness must be objective. As it was put in
Jacobs
and Another v Transnet Ltd t/a Metrorail
:
[53]
‘
It
is well established that an expert is required to assist the court,
not the party for whom he or she testifies. Objectivity is
the
central prerequisite for his or her opinions… “An expert
. . . must be made to understand that he is there to
assist the
Court. If he is to be helpful he must be neutral. The evidence of
such a witness is of little value where he, or she,
is partisan and
consistently asserts the cause of the party who calls him.”
[173]
Three
issues were separated for determination by this Court, the second
being whether the excavations carried out by the defendants
breached
any duty of lateral support and, thirdly, whether as a result of the
plaintiff’s property being so deprived of such
lateral support
on one or both of the defendants properties the scree slope on which
the plaintiff’s property and residence
was situated mobilised
and subsided in or about June 2008.
[174]
In
his written heads of argument the first defendant’s counsel
maintained this distinction between the second and third issue
but
characterised the third as being the question of whether there was
legal causation. In my view the second and third issues
overlap since
the issue of causation is integral to the question of whether there
was a breach of the duty of lateral support by
one or both of the
defendants. Accordingly I will address the two issues in the same
discussion although giving full attention
to the issue of causation
which is central to the first defendant’s arguments.
[175]
First
defendant’s counsel contended further that in large measure the
second and the third issue, which as I have said overlap,
fall to be
resolved on the basis of expert opinion evidence and that the facts
which are relevant are of limited scope and beyond
any material
doubt. Counsel for the first defendant correctly observed that the
main conflict of opinion between Dr McStay and
Dr Day were their
opposing contentions as to whether the slip circle slope failure was
caused by the removal of lateral support
or not. He submitted that Dr
McStay’s evidence was poor and could not be relied upon. His
criticisms in this regard were
built upon what were described as Dr
McStay’s dubious qualifications and expertise in relation to
the topic, his alleged
lack of independence or objectivity and his
propensity to tailor his evidence to suit the plaintiff’s case.
I have already
dealt with the challenge to Dr McStay’s
qualifications and his expertise in expressing the opinions which he
has done.
[176]
In
certain instances Dr McStay did stray somewhat beyond his field of
expertise such as expressing an opinion that Mr Naumann had
been
negligent in the manner in which he had gone about conducting the
excavations. This question, which in any event is not relevant,
would
fall within the Court’s purview. However, this predilection to
stray into areas of the Court’s authority was
not confined to
Dr McStay alone. Both expert witnesses expressed firm conclusions,
based on facts which were largely common cause,
as to whether there
was a failure of lateral support. That decision is, I consider,
ultimately one which must be made by the Court
and, although it may
be informed by scientific considerations, is not one where the Court
is entirely dependent upon, or can be
appreciably assisted by,
scientific evidence or opinions and must therefore evaluate and
choose between the conflicting opinions
of the experts.
[177]
The
overall conclusion as to whether there was failure of lateral support
is very much one which the Court can and must determine,
based on the
evidence in front of it, including, to the limited extent relevant,
the expert evidence. Put differently, even if
the only expert opinion
before the court was that of Dr Day’s, in my view the Court
would in principle be entitled to arrive
at the opposite conclusion,
namely, that there was a breach of the duty of lateral support.
Obviously the opposite position also
holds true, namely, if the only
expert opinion before the Court was that of Dr McStay’s, it
would not be precluded from reaching
the conclusion that there had
been no breach of the duty of lateral support. This point is borne
out by Dr Day’s evidence
that, notwithstanding his expertise
and learning in the area of lateral support and the fact that he had
co-written the Lateral
Support Code, there was no definition of
exactly what lateral support entails. This underlines the fact that
the question of what
constitutes, at least in law, lateral support or
a breach thereof is not an arcane or esoteric matter in which the
Court is unable
to formulate its own view without the assistance of
experts.
[178]
Counsel
raised other criticisms of Dr McStay’s evidence, namely that he
was not, and did not profess to be, an engineer and
was therefore not
qualified to do calculations for retaining walls and in respect of
lateral support. This criticism is partly
met by the remarks which I
have made above in respect of the concept of lateral support but also
by the fact that the details of
design and construction of the
retaining walls is in my view not fundamental to the questions which
the Court must determine.
[179]
A
further criticism of Dr McStay’s evidence was that his
investigation and evaluation was superficial and based on a reading

of evaluations, reports or accounts by others. In my view this is not
a fair criticism. Neither of the experts was a first-hand
witness to
the events of 2008/2009 and both of them had to rely on the reports
and evaluations of either their client or those
professionals who
preceded them in analysing and reporting on the problem. This leads
into the singular fact that neither party
called as an expert witness
the one person who appeared to be best qualified to express an
opinion on the circumstances leading
up to and surrounding the slip
circle failure of July/August 2008, namely, Dr Van Wieringen. He
played a critical role in the events,
having been instructed by all
parties to provide expert advice, and he was on hand as the critical
events unfolded in July/August
2008 and in subsequent months. The
fact that neither party saw fit to call him as a witness was puzzling
to say the least given
their repeated attempts to rely on
observations he made at the time as recorded in correspondence and
reports which were discovered.
[180]
One
criticism of Dr McStay’s evidence which does carry weight and
which reflects to some extent on his objectivity is the
about turn
which he made regarding the role of the excavations on second
defendant’s property. In his initial report, Dr
McStay
expressed the view that together both excavations had triggered the
slope mobilisation. In late February 2017, the plaintiff
concluded a
settlement with the second defendant. In a supplementary expert
summary filed on 3 March 2017, Dr McStay expressed
the further
opinion that the excavation on the Venter property had not caused or
contributed to the problem. Dr McStay sought
to justify his
changed opinion on the basis that he had not previously been aware of
the details of the timing and volumes of the
excavations on the two
properties belonging to the defendants. However when regard is had to
the dates of the hearing and the postponements
and when Dr McStay had
access to the relevant documentation, the indications are that his
change of opinion was probably at least
partly influenced by the
changed stance of the plaintiff towards the second defendant
following the settlement which had been concluded.
[181]
However,
similar criticisms can be directed at Dr Day’s evidence since
in my view he too identified too closely with his client’s
case
and failed at times to evince the objectivity which a court of law
expects from an expert witness. This propensity was illustrated
by Dr
Day’s reluctance to accept that the Dias property had been in
good structural condition prior to 2008 and his insistence,
based on
the scantiest of evidence, that the swimming pool had sustained
pre-existing damage, namely an alleged crack in the swimming
pool
which, it later transpired, was not there before 2008. Faced with
evidence that the plaintiff’s dwelling was in pristine

condition before 2008, Dr Day responded that he had ‘
difficulty
with that evidence’
.
However, as was pointed out by the plaintiff’s counsel, it is
for the Court to decide what the facts are and not for an
expert who
first saw the Dias property some seven years after the subsidence.
[182]
There
is no doubt that Dr Day is a recognised specialist geotechnical
engineer with a particular specialty in the field of lateral
support
and with considerable experience behind him. His CV speaks to the
eminence which he has achieved in his particular field
both through
his professional activities and his academic career. His reports were
also carefully drawn and reasoned. However,
the essential elements of
Dr Day’s opinion and the reasoning process which lay behind
must be identified and critically analysed.
As set out in the summary
of his evidence they are the following:
1.
The
damage to portions of plaintiff’s property was caused by
movement of the unstable hillslope on which the plaintiff’s

property was situated. That instability was the result of the
cumulative effect of the natural geotechnical features of the area,

the development and loading of the plaintiff’s property and
other properties in the area on the affected slope and a number
of
excavations into the slope dating back to the early 1980’s;
2.
The
movement of the already unstable slope at or about the end of July
2008 was triggered by the excavation of ground at the toe
of the
slope on the first and second defendants’ properties, combined
with surcharging on the top of the slope by the placement
of fill
material on the properties of the plaintiff and Babrow;
3.
Thus
the instability of the hillslope was not a consequence of the removal
of lateral support to the plaintiff’s property
as alleged but
of general instability of the hillslope;
4.
Any
failure or ground movement arising solely from the removal of lateral
support would have had only a localised effect i.e. would
have been
confined to the area immediately behind the retaining wall. No
failure of the ground was observed in such areas, confirming
that the
cause of the observed movement of ground was the result of general
instability of the slope rather than the removal of
lateral support;
5.
For
these reasons Dr Day is of the opinion that the scree slope on which
the plaintiff’s property and residence was situated
did not
mobilise and subside as a result of the removal of lateral support by
way of the excavation on the Naumann property;
6.
Prior
to the commencement of the excavation on the Naumann property, the
plaintiff and surrounding property owners contributed to
the
instability of the slope over several decades by the construction of
structures and the loading of surrounding properties,
in most
instances accompanied by the terracing of the sites. These activities
altered the natural state of the land;
7.
There
are a multiplicity of causes of the mobilisation and subsidence of
the scree slope from a geotechnical perspective. The evaluation
of
the extent and degree of the other contributing factors involves
complex, factual and geotechnical considerations.
[183]
Before
subjecting the main elements of Dr Day’s opinion to closer
scrutiny, two important general observations must be made.
The first
is that although Dr Day purported to confine himself to ‘
the
geotechnical and factual questions pertaining to lateral support’
,
implicit (if not explicit) in his opinion is the assumption that the
removal of lateral support must have a localised effect in
the sense
that its effects must be seen upon or in relation to the retaining
walls which were constructed on the first defendant’s
property.
The natural consequence of this assumption is that any failure of the
ground which reflects or manifests in a general
instability of the
hillslope was not regarded by Dr Day as a consequence of the removal
of lateral support to the plaintiff’s
property. Apart from the
question of whether these assumptions are logically or legally sound,
in my view they represent an intrusion
into what ultimately is the
Court’s domain, namely, a determination of whether the
excavation activities constituted a breach
of the duty of lateral
support owed to the plaintiff’s land. As was pointed out in
Linksfield
Park Clinic,
albeit in the context of the measure of proof, there are differences
in the approach of judicial officers and expert scientific
witnesses.
It is with some justification that the first defendant’s
counsel submitted that Dr Day’s view of what constitutes

lateral support could not be imposed upon the Court.
[184]
I
now turn to deal with particular statements or concessions made by Dr
Day in his evidence which tend to cast a different light
on the
central issue to be determined. These concessions related to the role
of the excavation on the first defendant’s property
on the slip
circle failure and the role and significance of the remedial measures
undertaken by or on behalf of the first defendant
after the major
ground movement in July/August 2008.
[185]
In
regard to the former, in short Dr Day was constrained to concede that
the excavations on the first defendant’s property
played a
significant role in the slope instability which manifested in
July/August 2008. Dr Day testified that it was clear that
‘
no
one is disputing that the excavations contributed to the failing’
;
the excavations were ‘
an
essential part of this failure’
and ‘
the
failure of the slope was the reason why the front portion of the Dias
property subsided’
.
Dr Day conceded that ‘
the
movement of both the Dias’ garden and the Dias’ house
were triggered or caused by the same set of circumstances
and are
related’
.
He conceded further that Mrs Dias’ evidence that before 7 June
2008 undulations had formed in her front garden and the ground
had
fallen away, constituted ‘
the
initial commencement of ground movement’
,
‘
that’s
when the slope started to move’
and ‘
the
slope started to talk to us’
.
In response to the question ‘
so
what was the major event post April 2008 that caused the distress?’
Dr
Day answered
that
‘the major event was the removal of ground which then set the
process of slope instability in motion, coupled with rainfall’
.
Finally, in response to the question ‘
so
Dr Day, is it not clear that, but for the Naumann excavations, the
land on the Dias property behind the Venter property would
not have
failed?’
Dr Day responded ‘
if
excavations had not been formed we wouldn’t be here today’
.
[186]
The
crucial role of the excavations on the Naumann property was
illustrated by the model which Dr Day constructed to illustrate
the
mechanisms of a slip circle failure and which is depicted in
photographs V1 to V4. It is only once block number 1, representing

the material excavated off the Naumann property, is removed that the
slip circle phenomenon occurs i.e. the bowl-shaped movement
leaving a
scarp and uplift at the toe, as is illustrated in photograph V2, or,
at the very least, is poised to occur awaiting one
or more further
triggering factors such as excess rains which reduce the shearing
strength of the soil. A further concession made
by Dr Day was that
the affected ground had mobilised downwards and outwards. ‘
It
moved both downwards, it settled in other words, and it moved down
the slope. This is within the mobilised area and that mobilised
area
extended below the outer edge of the pool’
.
[187]
The
conclusion reached by Dr Day, namely, that there was no failure of
lateral support, was more fully described by him when he
was
challenged in relation to the fact that the plaintiff’s
property had moved down slope as a result of the removal of lateral

support. His response was: ‘
I
do not believe that the primary cause was the removal of lateral
support because none of the vertical faces from which pressure
had
been removed underwent any form of failure. It was the removal of
weight from the lower portion of the slope…’
In this passage one sees, again, that Dr Day gives lateral support a
limited meaning, one apparently where the sideways (lateral)
force of
land is paramount. However, certainly seen from the perspective of
the complaining land owner, common sense would suggest
that whether
the damage-causing subsidence is the result of a loss of the downward
pressure of earth on the neighbouring (excavated)
property (but
nonetheless impacting on the stability of the neighbour’s land)
rather than the sideways pressure of the earth
(or both), is of no
practical relevance at all.
[188]
Dr
Day conceded that the bulk of the measures taken to arrest the slope
failure were implemented on the Naumann property. As emerged
from Mr
Naumann’s evidence these commenced with the installation of
plastic sheeting onto the garden of the Dias property
to prevent the
ingress of further water, the virtually immediate transporting back
to the Naumann and Venter sites of substantial
quantities of backfill
to replace the soil which had initially been excavated, the
installation of the soil anchors extending from
the middle retaining
wall on the Naumann property deep into the slope underneath the Dias
property, the installation of piles in
the middle terrace of the
Naumann property coupled with the casting of a 400mm thick concrete
slab over the piles as well as the
casting of a concrete wedge slab
between the middle and the top retaining walls which had the effect
of buttressing the foundation
of the back retaining wall.
[189]
All
these steps entailed expenditure of millions of rands on the part of
Mr Naumann or the first defendant and will apparently form
the
subject of a pending counter claim. It is of no little significance
in my view that many of these steps involved either adding
weight to
the Naumann property or using it as a launchpad from which to
stabilise the slope reaching into and under the plaintiff’s

property. It is also not without significance that in Dr Day’s
first report (
Exhibit
W
)
he stated as follows: ‘
Movement
monitoring shows that the installation of the anchors effectively
stabilised the Naumann excavation with minimal (<
2mm) further
down-slope movement being recorded on the retaining walls, the garden
in front of the Dias’ house and the southern
end of the Dias’
house after 25 November 2008’
.
At a later stage in that report he also recorded ‘
(i)n
all instances, the movement slowed significantly after 10 November,
after the ground anchors had been installed through two
of the
retaining walls on the Naumann property’
.
Dr Day conceded that certain structural cracks within the plaintiff’s
dwelling, the cracking of the pool, the patio and
in the front garden
were all associated with ground movements. In the light of the
evidence as a whole, to the extent that Dr Day
disputed that the vast
majority of the balance of the cracks and damage to the plaintiff’s
house were not caused by the ground
movement preceding and following
the slip circle phenomenon of late July, early August 2008, I find
that on the probabilities his
opinion cannot be sustained.
[190]
Despite
the voluminous evidence, the salient features of the matter were or
soon became common cause. In an experts meeting held
on 22 February
2016, Dr McStay, Dr Day and Ms Papanicolaou, as well as the first
third party’s engineer, agreed on amongst
others the following
salient points:
‘
Survey
matters
1.
The
zone of major slope movement recorded by the survey between end July
2008 to beginning September 2008 included the Naumann property,
the
front garden and the pool on the Dias property stopping short of the
house and most of the Venter property stopping short of
the
Venter/Stylemark boundary. The direction of the movement in this zone
is predominantly towards the sea (i.e. down-slope of
the plaintiff’s
property);
2.
There
has been a significant reduction in the rate of movement subsequent
to end November 2008 when the majority of the anchors
through the
Naumann retaining walls were installed. The upper retaining walls has
(sic) subsequently moved upslope by a few millimetres;
3.
There
may have been unrecorded movement prior to commencement of monitoring
on 26 or 28 July 2008.
Engineering
and Geotechnical considerations
9.
The formation of excavations on the Naumann and Venter properties
unloaded the toe of the slope causing movement
of the slope on one or
more failure surfaces; …
14.  It is
agreed that the slope is sensitive to disturbance and prone to
movement. Moffet and Day maintain there is evidence
of movement of
the slope dating back to the early 1980’s; …
16.  It is
agreed it is possible to develop on this slope if the correct
precautions are taken;…
21.
It is agreed that the installation of anchors and filling of cracks
on this site were appropriated
(sic)
actions.
(Day and Moffet do not agree that anchoring below adjacent property
and filling of cracks are ‘extreme measures’).
[191]
In
commenting on the two contrasting explanations for the slip circle
failure i.e. one large slip circle or a series of
en
echelon
slip circle failures, Dr McStay testified that:
‘
In
my view they both resulted from the removal of lateral support,
because its mechanism is the same. The one is deeper seated and
it
implies that the retaining walls retained a certain element of the
verticality and the whole soil moved as a mass whereas when
we start
looking at the detail of the measurements it is fairly obvious that
(there is) a lot of local scale deviations movement
from the survey
data and that the nature of the (indistinct) surfaces
themselves’
.
[192]
Dr
McStay’s opinion was that the cause of the damage was the
extensive excavations and their location which amounted to:
‘
the
removal of lateral support in the form of the earth and that was the
main triggering mechanism for the slope instability. Whether
that is
a series of small progressive failures behind that excavated site
plus the triggering of other deeper failure, appears
to be largely
irrelevant in terms of the actual (indistinct) mechanism itself. That
mechanism was obviously impacted by winter
rains, but that was
entirely foreseeable …’
[193]
As
Dr McStay explained ‘
once
you have a zone of soil which has been disturbed, it’s lost its
shear strength, then it has a knock-on effect in terms
of the
material behind it. The analogy would be a domino ferry when one
domino tipples over the next. And that is essentially what
happens
with slope failures. The first failure occurs, the soil mass is
weakened and then further failures occur until we finally
reach a new
point, the stable equilibrium’
.
[54]
[194]
Dr
McStay testified with regard to the heavy rain that occurred at the
end of July/August 2008 ‘
we
did find that in 2001 the rainfall figures were higher than in 2008.
So it does tend to suggest what we are dealing with, probably

something in the order of one in five year event’
.
It would certainly be ‘
within
the design consideration for any structures on the hillside to
maintain adequate drainage during construction and then after

construction to deal with that degree of rainfall. So you certainly
not put this into a category of act of God storm events’
.
[195]
Whilst
Dr Day was of the opinion that in engineering terms the upper
retaining wall built by Naumann served its function, Dr McStay
made
the common sense point in the context of the case that the function
of the retaining wall was to retain the earth behind it,
and by
inference, the property behind that as well. ‘
In
this instance although the concrete of the wall is still intact, it
did not perform its primary function of retention. It did
not provide
sufficient lateral support to stop lateral and vertical movement of
the soil and damage to the Dias property, therefore
it was not fit
for purpose.’
[196]
In
Dr McStay’s opinion the retaining walls were in a state of
failure because otherwise they would not have needed the remedial

measures which were put in place, being the anchoring and
buttressing. As explained in cross-examination by Dr McStay, an
excavation
inevitably involves the removal of lateral support. Dr
McStay testified that the fact that the excavations on the Naumann
property
had ‘
stood’
for some time, before they affected the Dias property was not
surprising as a ‘
lag
of two to three months before you see a failure is nothing remarkable
in terms of what I have experienced before with slopes.
The onset of
winter rains plays a critical role … I am not implying that
one day somebody digs a hole and the next day it
collapses. I don’t
see it as being that short term happening, as the bullet in the gun
scenario suggests but there is a longer
term which plays out here and
we have seen the recorded movement is not this immediate spontaneous
collapse. It takes place over
a period of time’
.
Notwithstanding a strenuous cross-examination Dr McStay remained
unmoved in his opinion that the deep-seated movement under the
first
defendant’s property was a slope failure triggered by the
removal of lateral support. As regards its timing his opinion
was
that with such a deep seated failure the scarp may appear quite
suddenly but that movement may have been occurring deeper within
the
soil for some time. The timeframe for the failure he opined ‘
would
coincide with the commencement and the bulk of the completion of the
excavation … as I said from the start of the excavation
to the
point of the failure at the scarp. It’s the entire period, it’s
not a single definitive event in time’
.
[197]
This
opinion would appear to tally with the plaintiff’s’
evidence that there was indeed movement below the feature rock
prior
to 7 June 2008, with that of Mr Naumann’s who testified that
the plaintiff’s Loffelstein wall collapsed on or
about 9 June
with the evidence that the pool rail pulled out from the wall on or
about 23 July 2008. This all provides clear evidence
of prior ground
movement.
The
evidence of Mr Van Gyssen on lateral support
[198]
It
was argued on behalf of the first defendant that Mr Van Gyssen was
called by the plaintiff principally to testify that the retaining

wall on the Naumann property had failed and had not replaced the
excavated earth as far as lateral support was concerned but that
he
had recanted in this view. This is not strictly correct since his
opinion as expressed in the summary of his first report and
opinion
did not deal with this subject and related principally to the
condition of the plaintiff’s house, the manner in which
it had
been designed and built and the effect upon it of the ground
movement. He was, however, as part of a supplementary report,
led to
comment on the report of the first third party’s expert who had
expressed the view that the retaining walls constructed
on first
defendant’s property had not failed and thus had successfully
replaced the removed earth as far as lateral support
was concerned.
Mr Van Gyssen initially expressed a contrary opinion on the basis,
correct insofar as it goes, that the lateral
walls had themselves
moved (although as part of the general body of earth involved in the
slip circle failure). When he was cross-examined
by the first third
party’s counsel on this subject Mr Van Gyssen testified that he
had not been aware of any general agreement
regarding the slip circle
issue which in any event was outside his field of expertise. When the
common cause facts were put to
him i.e. a mass movement of the earth
(in which the ground and the retaining walls moved together) he
expressed the view that in
that instance the wall itself ‘
most
probably did not fail’
.
In response to the Court’s questions Mr Van Gyssen indicated
that his concession that the top retaining wall had not failed
in its
purpose arose from the fact that he had not previously been aware of
the slip circle manifestation which was a geo-technical
issue the
mechanics of which were not within his field of expertise.
[199]
In
my view this ‘
concession’
on the part of Mr Van Gyssen does not take the matter much further
either way. He was expressing a view which fell outside his
field of
expertise and which, moreover, ultimately lies within the province of
the Court. The opinion which he was qualified to
give, namely, that
in his view the plaintiff’s dwelling was properly designed,
constructed and that the numerous defects
which he found in it on
inspection were the result of ground movement, appeared balanced and
was the result of investigations he
carried out. His evidence in this
regard is to be preferred to that of Dr Day and Mr Naumann on the
same subject.
The
essence of the first defendant’s argument
[200]
In
essence the first defendant argued that by 2008 the stability of the
slope upon which the plaintiff’s property rested,
and which
slope comprised various other properties, had been compromised by
development attributable to a variety of persons excluding
only the
first defendant, i.e. until excavations began on her property.
Bearing in mind that neither the plaintiff’s property
nor other
affected properties on the slope were in their natural state, the
argument proceeded, there was no
a
priori
duty of lateral support; secondly, it was further contended the duty
which the plaintiff sought to impute was one extending beyond
lateral
support owed to his contiguous property by the first defendant’s
property, to an (impermissible) duty to maintain
the entire slope.
[201]
These
arguments can be met at various levels. In the first place, if I am
correct in holding that the duty of lateral support in
our law is
owed to land and buildings, the presence on the plaintiff’s
property of a dwelling prior to the subsidence is
prima facie
irrelevant. Secondly, I am unable to accept the argument that the
plaintiff improperly seeks in effect to rely on a
duty on the part of
the defendants to support the entire slope on which all the affected
properties were situated. It is, in a
very real sense, merely
incidental to the plaintiff’s claim that what can be described
as a slope, and one comprising several
properties, subsided. The
plaintiff’s claim relates to her property alone and it is,
strictly speaking, irrelevant that the
subsidence which affected her
property also affected a number of neighbouring properties. The
question is whether the defendants
breached their duty of lateral
support towards her property. The fact that by means of the same
excavation/s they may have breached
their duty of lateral support to
other properties is in my view legally irrelevant to the present
matter.
[202]
The
first defendant repeatedly sought to characterise the plaintiff’s
case as one which relied upon a breach of the first
defendant’s
non-existent obligation to support the entire slope. But through
these contentions the first defendant was merely
reframing the duty
of lateral support relied upon by the plaintiff so as to characterise
the plaintiff’s cause of action
as falling outside of the scope
of a lateral support claim as it is generally known. The repeated
references to the manner in which
the plaintiff pleaded its case with
reference to the subsidence of the slope were similarly misconceived.
In paragraphs 4 –
7 of his particulars of claim the plaintiff
pleaded excavations by the defendants on their respective properties
in May, alternatively
June 2008, which excavations, he alleged,
deprived the plaintiff’s property of the lateral support to
which it was entitled.
In the crucial paragraph 8, the plaintiff
pleaded that in consequence of the aforesaid excavations ‘
the
scree slope on which the plaintiff’s property and residence is
situated and constructed mobilised and subsided through
the mechanism
of a shallow slip circle with uplift at the toe’
.
In paragraph 9, the plaintiff pleaded that the aforesaid mobilisation
of the slope and subsidence caused extensive damage to his
residence
and other improvements on his property.
[203]
A
reading of the pleaded allegations plainly reveals the plaintiff’s
case was that mobilisation and subsidence of the scree
slope was the
mechanism through which the failure to provide lateral support
manifested and caused the consequential damage to
the plaintiff’s
property. There is, generally speaking, no closed list of mechanisms
or manifestations of a failure to provide
lateral support to a
contiguous property. This was expressly recognised in
Gijzen
v Verrinder,
[55]
which involved an action for relief based on the removal of lateral
support. As in the present case the excavation complained of
was made
right up to the boundary line and the defendants maintained
throughout the trial that the plaintiff never had a cause
of action.
There was no evidence of any subsidence on the plaintiff’s land
at any one time along the boundary at the site
of the excavation. In
fact the evidence was that the loss of soil complained of by the
plaintiff was occasioned on an ongoing basis
by rain water and
erosion. Henning J held that:
‘
As
far as I have been able to ascertain the cause of the complaint in
reported cases based upon the deprivation of lateral support
has
usually been the subsidences caused in consequence thereof. By
subsidence I understand a falling down or caving in. Nowhere,

however, have I been able to find a statement to the effect that it
is essential for a cause of action based on the removal of
lateral
support that a plaintiff should establish that a subsidence in this
sense has occurred.’
[56]
[204]
In
the present matter the plaintiff’s land did indeed subside
although, as in
Gijzen
,
the face of no excavation failed. The fact is that notwithstanding
the construction of a total of three retaining walls by the
first
defendant, the plaintiff’s property moved laterally and
downwards towards the excavation on the Naumann property. In
the
event Henning J held that even the loss of soil as a result of rain
water and erosion was actionable on the grounds of the
removal of
lateral support. As the learned judge explained:
‘
In
the instant case the defendant excavated right up to the boundary
line, and in so doing effectively and directly impaired the
stability
of the plaintiff's property, a direct consequence of which was that
in the normal course of events the plaintiff was
bound to lose some
of his soil. I do not think that subsidence in the sense of a falling
down, collapsing or caving in of land,
is the only circumstance which
would warrant a plaintiff having a cause of action based on the
removal of lateral support. It is
no doubt true that in the vast
majority of cases damage is caused in this manner, but, in my
opinion, it would be unrealistic to
confine the right of action to
circumstances in which loss is occasioned in this particular manner.
I can see no distinction between
a situation where, following upon
the removal of lateral support, lumps of soil fall down during a
rainfall and a situation where
the soil is gradually eroded by rain
water. There is no magic in the word subsidence. In each of the
instances postulated there
would be a disturbance of the natural
surroundings of ground because of the removal of lateral
support.’
[57]
[205]
I
respectively associate myself with the reasoning of the learned judge
which I consider is authority for the proposition that there
is no
closed list of mechanisms through which a removal of lateral support
will manifest
vis-à-vis
a neighbouring property.
[206]
There
are further reasons why I am unable to accept the first defendant’s
argument that the subsiding of a slope on which
a number of
properties are situated, including a contiguous property whose owner
sues for a breach of the duty of lateral support,
falls outside of
the scope of such an action. One reason is the inherent illogicality
of the proposition that if an excavation
is of such large proportions
that it causes not simply a localised subsidence or failure but one
which undermines an entire slope
comprising multiple properties, then
the owner of a contiguous property cannot sustain an action based on
a breach of the duty
of lateral support. To accept this reasoning
would mean that a land owner whose excavation or breach causes
far-reaching damage
affecting a number of properties escapes
liability whilst land owners, the consequences of whose breach are
much more modest, are
saddled with strict liability.
[207]
A
further reason why I am unable to accept Dr Day’s opinion that
there was no failure of lateral support is the narrow definition

which he seeks to give to the concept of lateral support and the
artificial distinction which he seeks to draw between the vertical

and the horizontal pressure exerted by earth. In arguing that the
slope mobilisation was not a result of a lateral support, the
first
defendant relied on Dr Day’s opinion that, to quote from his
expert summary:
‘…
ground
movement was not caused by the removal of lateral support. It was the
result of a reduction of load at the lower end of the
slope leading
to a failure of the slope in which the excavation was formed, rather
than failure of the excavation itself…’
[208]
In
the same summary Dr Day proceeds further:
‘
The
formation of an excavation at the toe of the slope has two effects.
Firstly, it reduces the weight of the soil at the toe (B).
Secondly,
in the case of a soil that derives part of its strength from
friction, it reduces the shearing resistance of the soil
(C) over the
part of the failure plane below the excavated area. If the stability
of the slope prior to excavation was already
marginal, the formation
of the excavation could cause failure of the slope. Note that it is
not the excavation itself that fails,
but the slope in which the
excavation has been formed. It is thus a slope failure, not removal
of lateral support.’
[209]
Underlying
Dr Day’s opinion is the assumption or proposition that if the
excavation face itself does not fail then there can
be no failure of
lateral support, notwithstanding that the entire body of earth in
which the excavation is made itself shifts downwards
or laterally or
both, with the further consequence that neighbouring properties
relying for support on this body of earth move
laterally or downwards
with consequential damage. Dr Day did not provide any authority,
scientific or otherwise, for defining a
failure of lateral support as
being limited to the face of an excavation. Nor in my view does it
follow as a matter of logic or
science that such a limitation must be
placed on the concept of lateral support. The purpose of that support
is to protect the
integrity of contiguous land. In my view to limit
the duty of lateral support to circumstances where the face of an
excavation
fails, but to exclude the operation of a duty of lateral
support where the excavation remains intact but the property as whole
shifts through the mechanism of a land slide which causes contiguous
properties to move laterally or downwards, would be illogical
and
defeat the very purpose of the rule. It would moreover be artificial.
It is obvious that a body of soil exerts both downward
and lateral
pressure. In this regard Van Der Walt states as follows:
[58]
‘
Given
the natural downward and lateral pressure of the soil, it stands to
reason that artificially demarcated individual land parcels
must rely
on mutual lateral support to preserve the natural condition, position
and topography of each land parcel. When this support
is removed
through works or excavation on one property and the adjoining land
becomes unstable, the affected landowner is deprived
of the normal
use and enjoyment of her land.’
The
author writes further ‘
Badenhorst,
Pienaar and Mostert similarly take as their point of departure the
entitlement of every landowner to expect from neighbouring
landowners
“such support as would suffice to maintain his land in a
condition of stability”.
[59]
[210]
These
two passages provide support for the notion that the duty of lateral
support is not confined to such support as will maintain
the face of
an excavation irrespective of what further consequences an excavation
will have for the stability of contiguous land.
[211]
In
his evidence, Dr Day provided his own definition of lateral support
when he testified as follows:
‘…
when
you form an excavation you remove both the soil from the excavation,
which removes the weight of soil from the base of an excavation,
but
you also remove the lateral pressure which that soil exerts or
exerted before it was removed on the surrounding soils. …
Now lateral
support is that which you have to do to preserve the stability of
that face in the light of having removed that lateral
pressure.’
[212]
In
other words Dr Day removes from the operation of the duty of lateral
support the downward pressure of soil notwithstanding that
such
pressure can also play a role in preserving the stability of
contiguous land. In so doing Dr Day unjustifiably and illogically

conflates two separate concepts, namely, lateral support and the
lateral pressure of soil. Apart from the fact that Dr Day could
refer
to no working definition of lateral support, the only academic
article that he referred to provides no clarity on the question
of
what constitutes lateral support.
[60]
As mentioned, in his evidence Dr Day sought to distinguish a slope
failure from a failure of lateral support stating that the latter
is
confined to the area of excavation as opposed to a slope failure
which results in a global movement of an entire area. In this
context
he added that soil nails, which he hypothesised could be installed to
support the face of the excavation, would have ‘
absolutely
no influence on the stability of the slope because that entire
excavation is moving with the slope’
.
I pause here to point out that this is at odds with the evidence
(including Dr Day’s evidence) in the present case which
was
that movement in the slope as a whole reduced to little if anything
once all the remedial measures were taken by the first
defendant
immediately after the worst movements. These measures included ground
anchors and piles driven into the base of the first
defendant’s
property. Dr Day continued:
‘
So
it is not a failure of the excavation per se, it is a failure of the
slope encompassing the excavation. So that is my distinction
between
a lateral support failure which is a failure of the excavation face
and a slope failure which is an overall failure which
encompasses the
entire excavation and any retaining structure which is built to
support that excavation.’
[213]
On
behalf of the first defendant it was contended that Dr McStay’s
opinion that ‘…
the
causative mechanism of the ground movements was a triggering of a
slope failure due to the removal of lateral support by excavation
of
a large mass of soil and boulders on 13 and 11 Barbara Road’
was
a bald
ipse
dixit
lacking any authority or reasoning. It was further criticised on the
basis that his evidence lacked any explanation of what constituted

lateral support. However, Dr McStay did testify that the cause of the
damage was the extensive excavations and their location which

amounted to ‘
the
removal of lateral support in the form of the earth and that was the
main triggering mechanism for the slope instability’
.
Dealing with the fact that the retaining wall on the boundary of the
Dias property had not failed he testified that ‘
in
this instance, although the concrete of the wall is still intact, it
did not perform its primary function of retention. It did
not provide
sufficient lateral support to stop lateral and vertical movement of
the soil and damage to the Dias property, therefore
it was not fit
for purpose’
.
[214]
Ultimately
what was presented to the Court were the opinions of two geotechnical
engineers. One asserted that a failure of lateral
support must
manifest at the face of the excavation and that if an excavation
results in a general landslide but no failure of
the excavation
surface, then it is not a failure of lateral support. On the other
hand the plaintiff’s expert took an opposing
point of view,
namely, that the fact that the retaining wall stood and therefore
there was no failure of the face of the excavation
did not mean that
there was no failure of lateral support where the excavation was
instrumental in a wholesale landslide which
led to lateral and
downward movement of the plaintiff’s property. In that instance
the retaining wall had failed to perform
its overall function which
was to ensure the stability of the property behind it.
[215]
It
was further argued on behalf of the first defendant that the
retaining walls constructed on Naumann’s property did not
fail
and successfully retained the soil that was behind it; furthermore,
that it is not the function of a retaining wall, whose
overt purpose
is to provide lateral support – to hold back a slip circle
movement. The flaw in this argument is the assumption
that the duty
of lateral support is exhaustively satisfied by the building of
retaining walls which remain standing. However, if
in a given
situation the contemplated excavation is of such an extent that a
slip circle failure might occur which will not be
prevented by the
construction of  a retaining wall or walls, then quite clearly
the duty of lateral support requires more
extensive preventative
measures in order to be satisfied. As the circumstances of the
present case indicate these measures were
available in the form of
piles, ground anchors, better timing of the entire building project
etc., measures which were in some
instances successfully implemented
albeit
ex
post facto
.
[216]
The
thrust of the first defendant’s case, with which the first
third party associated itself, was expressed in the following

passages from Dr Day’s evidence when it was put to him that the
bulk of the earth removed in the excavation provided lateral
support
to the plaintiff’s property and not just the excavation face.
He answered as follows:
‘
The
failure which we had was a failure which encompassed five properties.
We are not talking about something which occurred in one
localised
area. We are talking about the mobilisation of a slope. The primary
cause for the mobilisation of that slope was the
removal of the
vertical load afforded by the soil, above the failure plane, within
the two excavations on the Venter property and
the Naumann
property’
.
[217]
It
was then again put to Dr Day that the bulk of earth that was removed
was providing lateral support to the Dias property and he
replied:
‘…
M’Lord,
yes, the earth did provide lateral support to the Dias property in
that when you have a weight of ground you have
horizontal forces
acting within that ground. The question is whether there is any nexus
between the removal of the horizontal component,
that lateral
component and the failure of the slope and the answer there is no.
There is absolutely no nexus between the two. The
cause of the
failure of the slope is a removal of weight and not the removal of
any lateral support’.
[218]
Dr
Day continued:
‘
No,
the excavations were an essential part of this failure. They were one
of the contributing factors to the failure and no one
is denying
that. The question is whether or not it is removal of lateral support
or a slope failure.
Mr Bey: And as I
understand your distinction is, you say lateral support is horizontal
pressure and anything that has to do with
vertical pressure you say
is irrelevant in the debate of lateral support. Is that correct? …
My Lord, yes, the word lateral
means sideways.
And that is your
engineering approach to this?
…
No
My Lord, it is a dictionary definition.’
[219]
In
my view Dr Day errs when he concludes that a failure on the
contiguous property caused primarily or exclusively by the removal
of
the vertical pressure of soil does not constitute a failure of the
duty lateral support. This is to unjustifiably and artificially
limit
the concept and the doctrine of lateral support. Even if Dr Day’s
viewpoint was scientifically accepted this does not
necessarily mean
that the Court is bound to accept it as defining the scope of the
duty of lateral support in law.
[220]
Finally,
it was argued on behalf of the first defendant that the vertical
forces in question related to the slope as a whole, encompassing
five
properties, and not just to the adjacent Dias property with the
result that even if the weight countering these vertical forces
could
be viewed as some form of ‘
lateral
support’
the fact that it supported the entire slope and not simply the
plaintiff’s property took it out of the realm of the duty
of
lateral support. However, I have already considered and rejected the
argument that a failure of lateral support can only be
localised and
therefore that failures of a slope encompassing several properties
precludes the (strict liability) duty of lateral
support.
[221]
In
my view the dispute between the experts turns on the question of
whether lateral support is to be given a wide or a narrow definition.

In the narrow definition any vertical force removed as a result of an
excavation is irrelevant; provided the vertical face of no
excavation
fails, the duty of lateral support is satisfied. I am aware of no
precedent or authority for affording the concept of
lateral support
this narrower definition. It is, furthermore, neither a purposive nor
sensible interpretation since it does not
protect the interests of
the contiguous land owner whose primary concern in these
circumstances is the stability of his property,
irrespective of
whether his neighbours’ excavation removes that stability
through the failure of the vertical face of an
excavation or through
the removal of weight at the toe of the slope causing a general
landslide or slip circle failure. Ultimately,
notwithstanding the
spirited debate and differences of opinion between the experts and
although I have engaged with them
ex
abundante cautelae
,
I consider that the question of the extent of the duty of the
definition of lateral support is a question which can be determined

by the Court and in which expert scientific opinion has at best a
limited role to play.
[222]
In
my view, Dr Day’s distinction between the failure of an
excavation face and the failure of a slope in a greater body of
soil
as a manifestation of a failure of lateral support is illogical and
does not appear to have scientific authority. For the
reasons
furnished above I consider that lateral support must be given the
wider, purposive definition, one congruent with the role
which the
doctrine plays in our law, namely, a special remedy which safeguards
the integrity and stability of contiguous land.
Although I consider
that the question of whether the slip circle failure constituted a
failure of lateral support could be answered
without recourse to the
evidence of the experts, I have fully engaged
with
their evidence. It is therefore incumbent on me to evaluate Drs
McStay and Day as witnesses. Apart from Dr McStay’s rather

unconvincing about turn in regard to the role of the excavation on
the Venter property, I was favourably impressed by his evidence
as a
whole. The opinions which he expressed were rational and backed by
consistent reasons. What came through in his reports and
evidence was
a practical and common sense approach which demonstrated his wide
experience in the field. This was well illustrated
in my view by his
observations regarding the hazards of building on the Camps Bay slope
and the cautious approach which this necessitated
as well as his
observations disputing the success of the retaining walls on the
Naumann property simply because they remained standing.
The
proposition (which he disputed) that they were successful in their
function notwithstanding the slope circle failure puts one
in mind of
the mythical surgeon proclaiming an operation a complete success –
apart from the fact that the patient did not
survive.
[223]
As
far as Dr Day is concerned there is no doubting his expertise as a
geo-technical civil engineer and his evidence was very helpful
in
understanding the geological aspects of what took place on the site
from March 2008 until the remedial measures were completed.
Although
I do not doubt Dr Day’s sincerity or his professional
integrity, I gained the distinct impression that he became
overly
wedded to his client’s case, including the notion that the
geological event was not a failure of lateral support.
Dr Day’s
unwillingness to accept that the Dias dwelling was not in excellent
condition prior to 2008, based on speculative
or weak evidence
indicating the contrary, suggested that he fell into the trap of
approaching some of the issues in the matter
in a less than balanced
manner.
Causation
[224]
A
further defence or legal argument raised on behalf of the first
defendant was the issue of causation, the overall contention being

that the plaintiff had failed to discharge the onus of proving this
requirement.
[225]
The
first element of the argument was the contention that the central
issue before the Court was not whether the slope mobilisation
was
caused by the Venter and/or Naumann excavation but instead was
whether the slope mobilisation was caused by a removal of lateral

support on the Venter and/or Naumann properties. I have already
found, however, that a removal of lateral support can manifest
as a
slope mobilisation.
[226]
In
the second part of the argument, the first defendant’s counsel
dealt with what he contended was the multiplicity of factors
which
caused the slope mobilisation. Counsel referred to the two
requirements of causation as an element of liability
viz
factual causation, requiring a factual enquiry whether the relevant
act or omission caused the harm giving rise to the claim and,

secondly, legal causation, being the question of whether the relevant
act or omission was sufficiently closely or directly linked
to the
harm for legal liability to ensue.
[227]
Reliance
was placed by the first defendant on the case of
Lee
v Minister of Correctional Services
.
[61]
In that case the Constitutional Court approved the
sine
qua non
or ‘
but
for’
test long employed by the Courts in determining factual causation
notwithstanding its dictum that the ‘
test
is not without problems, especially when determining whether a
specific omission caused a certain consequence’
.
[62]
The Constitutional Court went on to state—
[63]
‘
(i)n
the case of “positive” conduct or commission on the part
of the defendant the conduct is mentally removed to determine
whether
the relevant consequence would still have resulted. … However,
as will be shown in detail later, the rule regarding
the application
of the test in positive acts and omission cases is not inflexible.
There are cases in which the strict application
of the rule would
result in an injustice, hence a requirement for flexibility. The
other reason is because it is not always easy
to draw the line
between a positive act and an omission. Indeed there is no magic
formula by which one can generally establish
a causal nexus. The
existence of the nexus will be dependent on the facts of a particular
case.’
[228]
Clearly
factual causation must be proved notwithstanding the fact that the
claim is for a failure of lateral support where liability
is strict.
The test was classically set out in
International
Shipping Company (Pty) Ltd v Bentley,
[64]
where Corbett CJ stated in the following terms:
‘
The
enquiry as to factual causation is generally conducted by applying
the so-called “but-for” test, which is designed
to
determine whether a postulated cause can be identified as a causa
sine qua non of the loss in question. In order to apply this
test one
must make a hypothetical enquiry as to what probably would have
happened but for the wrongful conduct of the defendant.
This enquiry
may involve the mental elimination of the wrongful conduct and the
substitution of a hypothetical course of lawful
conduct and the
posing of the question as to whether upon such an hypothesis
plaintiff's loss would have ensued or not. If it would
in any event
have ensued, then the wrongful conduct was not a cause of the
plaintiff's loss; aliter, if it would not so have ensued.’
[229]
Nugent
JA, in
Minister
of Safety and Security v Van Duivenboden,
[65]
stated as follows:
‘
A
plaintiff is not required to establish the causal link with
certainty, but only to establish that the wrongful conduct was
probably
a cause of the loss, which calls for a sensible
retrospective analysis of what would probably have occurred, based
upon the evidence
and what can be expected to occur in the ordinary
course of human affairs rather than an exercise in metaphysics.’
[230]
First
defendant’s counsel argued that a primary cause of the slope
mobilisation in July 2008 was general slope instability
predating the
Naumann and Venter excavations and that its instability was the
result of a number of historical factors including
poor soil
conditions, prior excavations on the Venter and Stylemark properties
and finally a winter with a significantly high rainfall
intensity.
For the purposes of dealing with this argument all these contributing
factors can be accepted as having played a role.
Counsel also argued
that the Venter excavations in 2008 would have exacerbated what was a
pre existing problem on the property.
In this context it was
contended that the Naumann excavation was but one of a multiplicity
of contributory causes.
[231]
This
picture, however, does not do justice to the facts. It is clear that
the excavation on the Naumann property was extensive.
It was
described by Naumann’s own engineer as ‘
a
hole the size of which (he) had never to dig before’
and involved the removal of approximately 5413m³ of earth, 57
blasting shots as well as the removal of many large boulders.
On the
adjoining Venter property, 574m³ were removed in the excavation
which required 22 blasting shots. When the slip circle
failure
occurred 1057m³ of fill was brought back by Mr Naumann and
deposited on the two sites to stabilise the slope. In numerous

passages in his evidence, Dr Day conceded that without the
excavations on the Naumann (and Venter) properties the slip circle
failure would never have occurred. The multiplicity of factors which
were identified by first defendant’s counsel were, save
for the
winter rainfalls (themselves quite predictable), part of a
pre-existing state of affairs.
[232]
It
was argued on behalf of the first third party that there was no clear
direct and exclusive link between the Naumann excavations
and the
slip circle earth mobilisation during 2008. In support of this
argument it was pointed out that the excavations on both
properties
stood unsupported for some months without incident. There may well
have been no apparent subsidence or earth movement
for a period of
time after the excavations were complete but once the winter rains
fell (and around the time the Loffelstein wall
collapsed), the ground
movements which led to the slip circle commenced apace. The
suggestions that the 1980 Venter excavations
had already brought the
slope ‘
to
the point of failure’
,
a submission made by both first defendant and the first third party
on several occasions, is grossly overstated and unsupported
by the
evidence.
[233]
In
the present case the exercise prescribed in
Bentley
presents no difficulty; had the first defendant not effected his
excavation, the overwhelming probability is that no slip circle

failure would have occurred. Although not strictly relevant, it is
also probable that had the excavation been effected but only
after
expert geo-technical engineering advice had been taken and with
appropriate safeguards such as ground anchors, piles or other

measures, the slip circle failure would similarly not have taken
place. In these circumstances I see no difficulty at all with
the
question of factual causation. If the fact of excavations on the
Naumann property (and on the Venter property) in 2008 is thought
away
it is quite clear that the slip circle failure would never have
occurred.
[234]
It
is doubtful whether it is necessary to have regard to the question of
legal causation since liability under the duty of lateral
support is
strict and the question of reasonable foreseeability does not arise.
Indeed first defendant’s counsel himself
contended, at an
earlier junction in his heads of argument, that both fault and
foreseeability were irrelevant inasmuch as there
were no allegations
in the particulars of claim regarding these aspects and the plaintiff
advanced a cause of action predicated
on strict liability. Even if
legal causation had to be proved then in my view that requirement is
fully satisfied. Given the extent
of the excavation which Mr Naumann
planned and the topography of the terrain in which his property was
situated, it was obviously
foreseeable that difficulties such as
those which came to pass might arise. That this was recognised by Mr
Naumann himself and
his consulting engineers emerges, if only
belatedly, from the correspondence which passed between them during
May and July 2008
during the course of the excavation and which is
set out in paragraphs 91 – 94 above. This correspondence speaks
for itself
concerning the foreseeability of slope stability/lateral
support issues.
The consent/waiver defence
[235]
This
issue was not strenuously pursued by counsel in argument but it was
not abandoned so I shall deal with it. The first defendant
contends
that her property owed no duty of lateral support to the plaintiff’s
property because the plaintiff had agreed that
the excavations could
be carried out and thus consented to the removal of earth providing
lateral support, and its replacement
with retaining walls. It is so
that the first defendant sought and obtained the written approval of
surrounding property owners,
including the plaintiff, for the
construction of the dwelling she proposed to build and that this
included the excavation. However,
in clause 2.7 of the self-same
agreement the first defendant and her husband, Mr Naumann, (referred
to therein as ‘the applicants’)
undertook to ‘
ensure
security integrity of neighbouring properties during the construction
phase’
.
That would necessarily include the duty to ensure that any excavation
did not cause a failure of lateral support to neighbouring
properties
including the plaintiff’s. In any event, although it is a
well-established principle that a right to lateral support
can be
waived and lost, as was stated in
Rouliot
any such waiver or loss would not be presumed and has to be clearly
established. The following passage appears in that judgment:
‘
If
the right of lateral support exists as a natural right incident to
the plaintiff’s land – as in my opinion it does
–
the parties to the contract must be deemed to have contracted with a
view to the continued existence of that right. If
they had intended
that the plaintiff should be deprived of this natural right ought not
the defendant have stipulated to that effect?
I am of the opinion
that in the absence of such a stipulation the presumption is in
favour of an intention to preserve a well-established
natural right
of property rather than to part with such a right’
.
[66]
[236]
A
reading of the agreement concluded between the first defendant and
her neighbours contains no direct reference to the excavation
let
alone a stipulation that neighbours were foregoing their right to
lateral support. The onus to establish a waiver of the right
to
lateral support rests upon the defendant who pleads it.
[67]
[237]
In
heads of argument the defence pleaded by the first defendant that the
plaintiff had consented to the first defendant’s
excavation and
thereby waived any right of lateral support was watered down to the
contention that the plaintiff had agreed that
the excavations could
be carried out and had thus consented to the removal of earth
providing lateral support and its replacement
with retaining walls.
These are two different concepts however and even the latter does not
equate to a waiver of any right of
lateral support. In my view the
first defendant has failed to prove that the plaintiff waived his
right to the lateral support
which his property was owed.
The
position of the second defendant
[238]
The
plaintiff’s action initially sought to hold the first and
second defendants jointly and severally liable for his damages.
The
action was initially opposed by the second defendant who was
represented by counsel during the early stages of the trial. When
the
matter recommenced after a postponement the second defendant was no
longer represented and the plaintiff’s counsel advised
that the
plaintiff had settled its claim against the second defendant. At this
stage Mrs Dias was still under cross-examination.
In due course the
plaintiff filed a notice of withdrawal of his action against second
defendant which says no more than this had
occurred pursuant to a
settlement concluded between the parties. During argument the
question arose as to the effect of the plaintiff’s
purported
withdrawal of its action against the second defendant on any relief
which the plaintiff might obtain. On behalf of the
plaintiff it was
contended that with effect from filing the notice of withdrawal,
namely, 24 February 2017, there was no longer
any
lis
between it and the second defendant, that it sought no order as
against the second defendant and accordingly that no such order
could
be granted.
[239]
Two
difficulties arise with regard to this proposition. In the first
place the order made by Saldanha J in terms of Rule 33(4) identified

the prior issues to be determined which also involved a consideration
of the role and liability of the second defendant in his
capacity as
owner of a neighbouring property at the relevant time. That order has
never been amended and should the issues be decided
in favour of the
plaintiff as against the first and second defendants then the first
defendant might well have a right of recourse
against the second
defendant.
[240]
The
second difficulty with the plaintiff’s approach is that his
notice of withdrawal against the second defendant was a unilateral

act which did not enjoy the consent of the first defendant or the
first third party, nor that of the Court. Rule 41(1)(a) of the

Uniform Rules of Court provides as follows:
‘
A
person instituting any proceedings may at any time before the matter
has been set down and thereafter by consent of the parties
or leave
of the Court withdraw such proceedings, in any of which events he
shall deliver a notice of withdrawal …’
[241]
In
the commentary in
Erasmus
Superior Court Practice
,
[68]
the authors state that in the absence of such consent or leave, a
purported notice of withdrawal will be invalid. More significantly

they add ‘
the
court has a discretion whether or not to grant such leave, and the
question of injustice to the other parties is germane to
the exercise
of the court’s discretion. It is, however, not ordinarily the
function of the court to force a person to proceed
with an action
against his will or to investigate the reasons for abandoning or
wishing to abandon one’
.
[69]
In
Karoo
Meat Exchange Ltd v Mtwazi,
[70]
it was held that once the state of set down has been reached in
litigation a discretion vests in the judicial officer as to whether

the proceedings should be terminated or not. To hold otherwise, to
allow the plaintiff an absolute and not a qualified right to

terminate the action at will, might lead to injustice. In this regard
Diemont J stated as follows:
‘
Once
the case has been set down for hearing the Court has an interest to
see that justice is done both in regard to the merits of
the dispute
and in regard to the costs. When the case has progressed to the stage
of being set down for hearing, the parties can
no longer do as they
please. The Court cannot be deprived of its control merely by reason
of the fact that the plaintiff has served
a notice of withdrawal. …
[T]hese considerations persuade me that it is right and proper that
once the stage of set down
has been reached in litigation a
discretion should vest in the judicial officer as to whether the
proceedings should be terminated
or not. To hold otherwise, to allow
the plaintiff an absolute and not a qualified right to terminate the
action at will, may lead
to injustice’.
[71]
[242]
The
rationale for this approach and for the rule is well illustrated in
the present case. The first defendant, and quite conceivably
the
first third party as well, have an interest in determining, should
they be held liable for any damages, whether the second
defendant may
also be liable for damage suffered by the plaintiff. Should the
second defendant be treated in these proceedings
as if he were no
longer a party thereto by reason of the settlement agreement arrived
at and the plaintiff’s notice of withdrawal
against him, the
first defendant and the first third party may have to institute
separate proceedings against the second defendant
or alternatively
join him at this late stage as a further third party. All these
issues could have been fully ventilated had the
plaintiff sought the
consent of the first defendant and the first third party to the
withdrawal of his action against the second
defendant or had the
Court been approached for its consent. In that event, had the
plaintiff been successful the order made by
Saldanha J separating the
issues and including the second defendant within the ambit of those
issues could have been amended. None
of these steps were taken. The
plaintiff simply purported to withdraw his action against the second
defendant irrespective of the
outcome
vis-à-vis
the first defendant and the first third party.
[243]
In
my view the present circumstances illustrate why the plaintiff does
not have an unqualified right to withdraw his action against
the
second defendant. I should mention that the possibility that the
Court could ultimately make an order which affected the second

defendant was conveyed to his legal representative shortly after the
filing of the notice of withdrawal but they chose to take
no further
part in the trial. In the result the form of the draft order sought
by the plaintiff in which the second defendant is
excluded cannot be
granted.
[244]
The
view that I take then is that the issues as defined by Saldanha J
must be answered insofar as they apply to the second defendant
as
well. As I have indicated in my reasoning each of the three issues
separated in terms of Rule 33(4) must in my view be answered
in
favour of the plaintiff.
The
second defendant’s liability
[245]
It
remains to determine whether any liability on the part of the second
defendant has been established on the evidence for any damages
which
may have been suffered by the plaintiff.
[246]
In
the first place it was common cause that the Venter property bordered
on the plaintiff’s property and therefore its owner
owed a
common law duty to provide lateral support to the plaintiff’s
property. In regard to the second and third issues,
in my view the
evidence has established that the excavations which were carried out
on the second defendant’s property in
or about May or June 2008
breached this duty of lateral support. This was the view initially
expressed by Dr McStay on behalf of
the plaintiff and there was no
countervailing evidence from the second defendant. Dr McStay’s
view only changed in this regard
subsequent to the plaintiff arriving
at a settlement agreement with the second defendant. Furthermore, Dr
McStay’s reasons
for the change in his opinion were not
convincing and there was no cogent evidence supporting his revised
opinion in this regard.
Although the excavation on the second
defendant’s property was relatively small in comparison to that
on Naumann’s
property, on the probabilities it must have
contributed towards the overall loss of stability in the slope and
was a manifestation
of a failure to provide appropriate lateral
support to the plaintiff’s property. The failure of the slope
impacted severely
on the second defendant’s property and the
movement of the plaintiff’s house was both downwards and in the
direction
of the second defendant’s property. In these
circumstances, although it is not possible on the evidence put before
the Court
to determine precisely to what extent the respective
excavations led to or contributed to the slip circle failure, on the
probabilities
the excavations on Venter’s property played a
material role in rendering the slope unstable.
Costs
[247]
Given
that the plaintiff has been successful in respect of each of the
three separated issues he is entitled to the costs of the
trial.
Since the action was defended by both the first defendant and the
first third party it is appropriate that they bear the
plaintiff’s
costs jointly and severally.
[248]
The
costs of the Rule 33(4) application were reserved for determination
by the trial court. That application was brought by the
first
defendant and the first third party and opposed by the plaintiff even
though he too considered that certain issues should
be separated. The
grounds of opposition were that the plaintiff wanted certain further
issues added to those to be heard first.
It would appear that the
Court did not favour the plaintiffs’ approach in this regard
although it did grant him some relief
which found expression in the
wording of paragraph 2 of the order. In the circumstances, I consider
that the plaintiff should pay
two thirds of the first defendant’s
and first third party’s costs in that application.
[249]
In
the result the following order is made:
1.
It
is declared that:
1.1
The
first and second defendant owed the plaintiff a duty to provide
lateral support to the plaintiff’s property;
1.2
The
excavations carried out on the first defendant’s and the second
defendant’s property in May or June 2008 breached
this duty of
lateral support, as a result whereof the scree slope on which the
plaintiff’s property and residence were situated
and
constructed, mobilised and subsided in or about June and July 2008.
1.3
The
first defendant and the first third party are, subject to para 1.4
below, to pay the plaintiff’s costs jointly and severally,
the
one paying the other to be absolved, including the qualifying
expenses of Ms Papanicolaou, Dr McStay and Mr Van Gyssen.
1.4
In
relation to the separation application the plaintiff is to pay two
thirds of the first defendant’s and first third party’s

costs therein.
_____________________
BOZALEK
J
APPEARANCES
For
the Plaintiff

:           Adv RWF
MacWilliam (SC)
As
Instructed
by
Smith
Tabata Buchanan Boyes
For
the 1st Defendant

:           Adv JG
Dickerson (SC)
Adv
M Steenkamp
As
Instructed by
Edward
Nathan Sonnenbergs
For
the 2nd Defendant

:           Adv L
Wessels
As
Instructed
by
Werksmans
Attorneys
For
the 1st Third Party

:           Adv M Seale
(SC)
As
Instructed
by
Mellows
& De Swardt
For
the 6th Third Party

:           Adv S
Olivier (SC)
As
Instructed by
Hardam
& Associates
[1]
2007 (5) SA
94
(SCA) at para 16.
[2]
Anglo
Operations Ltd v Sandhurst Estates (Pty) Ltd
2007
(2) SA 363 (SCA).
[3]
1963 (1) SA 102 (A).
[4]
(1890-1891) 8
SC 74.
[5]
Ibid
at
91.
[6]
Ibid
.
[7]
2007 (2) SA 363 (SCA).
[8]
Ibid
at
para 14.
[9]
Ibid
at
para 8.
[10]
1911 TPD 577.
[11]
Anglo Operations
at
para 14.
[12]
Ibid
at
para 17.
[13]
1951 (4) SA 466
(E) at 474.
[14]
See
JRL
Milton
The Law of
Neighbours in South Africa
1969 Acta Juridica 123
–269 (‘
Milton’
)
at 200.
[15]
(1894) 1 Off
Rep 43
(‘
Victoria’
).
[16]
Ibid
at
48.
[17]
Phillips v
South African Independent Order of Mechanics and Fidelity Benefit
Lodge and Brice
1916 CPD 61
at 65.
[18]
[1920] LKCA 62
;
(1901) 22 NLR 225
at 227.
[19]
1951 (4) SA 466
(E) at 474A–B.
[20]
Ibid
at
484C-E.
[21]
1955 (2) SA
312 (N).
[22]
Ibid
at
316B-C.
[23]
1955 (1) SA 634
(N) at 638B-D.
[24]
The Law of
Neighbours
,
Juta, 1
st
ed, Chapter 3 at 92.
[25]
Ibid
at
122-3.
[26]
Ibid
at
123-4.
[27]
Ibid
at 122. See
Milton
at 200.
[28]
Above a
t
473G.
[29]
Ibid
at 484 A-D.
[30]
Ibid
a
t 484E and H.
[31]
Ibid
a
t 485F.
[32]
Above.
[33]
(
1881)
6 AC 740.
Lord
Penzance said that if the question had not been governed by
precedent he would have held that ‘…
it would not be
inconsistent with legal principles to hold, that where an owner of
land has used his land for an ordinary and
reasonable purpose, such
as placing a house upon it, the owner of the adjacent soil could not
be allowed so to deal with his
own soil by excavation as to bring
his neighbour's house to the ground. It would be, I think, no
unreasonable application of
the principle "sic utere tuo ut
alienum non laedas" to hold, that the owner of the adjacent
soil, if desirous of excavating
it, should take reasonable
precautions by way of shoring, or otherwise, to prevent the
excavation from disastrously affecting
his neighbour. A burden would
no doubt be thus cast on one man by the act of another done without
his consent. But the advantages
of such a rule would be reciprocal,
and regard being had to the practicability of shoring up during
excavation, the restriction
thus placed on excavation would not
seriously impair the rights of ownership.’
[34]
Milton
at
208.
[35]
Ibid
at
209.
[36]
Ibid
.
[37]
Ibid.
[38]
Law of Neighbours
above,
at 124.
[39]
Above at 124
– 5 with reference K Gray and SF Gray Elements of Land Law,
5
th
ed, (2009) 1.2.29 and the case of Xpress Print Pte Ltd and L&B
Engineering (S) Pte Ltd [2000] 3 SLR 545.
[40]
Milton
at
209.
[41]
Ibid
at
210.
[42]
Ibid
.
[43]
1947 (3) SA
602 (T).
[44]
Ibid
at
209.
[45]
Anglo Operations
at para 17.
[46]
Milton
at
210.
[47]
Above.
[48]
Ibid
at
106H-107A.
[49]
Ibid
at
108E.
[50]
Rex v Vilbro and Another
1957 (3) SA 223
(A) and Zeffert
and Paizes
The
South African Law of
Evidence
, 2
nd
ed, at 321-3.
[51]
P v P
2007
(5) SA 94
(SCA) at para 16.
[52]
Michael and Another v
Linksfield Park Clinic (Pty) Ltd and Another
2001
(3) SA 1188
(SCA) and Zeffert and Paizes at 323.
[53]
2015 (1) SA
139
(SCA) at para [15] quoting
Stock
v Stock
1981 (3) SA 1280
(A) at 1296F.
[54]
See para
217.10 of the plaintiff’s heads and pages 1405 – 1420 of
the record.
[55]
1965 (1) SA 806 (N).
[56]
Ibid
at
810E.
[57]
Ibid
at 810 H–811
C.
[58]
Law of
Neighbours
at 88.
[59]
Ibid
.
[60]
Clough GW and O’Rourke TD
(1990)
Construction
induced movement of insitu walls.
Design and Performance of Earth retaining structures, Geotechnical
Special Publication 25. ASCE, New York.
[61]
2013 (2) SA
144 (CC).
[62]
Ibid
at
para 40.
[63]
Ibid
at para 41.
[64]
1990 (1) SA
680
(A) at para 65 (700 F–G).
[65]
2002 (6) SA
431
(SCA) at para 25.
[66]
Rouliot
above
at 94.
[67]
Laws v
Rutherford
1924 AD 261
at 263 and
Road
Accident Fund v Mothupi
2000 (4) SA 38
(SCA) at para 19.
[68]
Vol 2, at
D1-550.
[69]
Ibid
.
[70]
1967 (3) 356
(E).
[71]
Ibid
at
359B-G.