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- Unreported Judgment
QUEENSLAND CIVIL AND ADMINISTRATIVE TRIBUNAL
Beikoff v Queensland Building and Construction Commission  QCAT 377
QUEENSLAND BUILDING AND CONSTRUCTION COMMISSION
General administrative review matters
22 September 2020
21 October 2019
27 November 2019
Member Paratz AM
The decision of the Queensland Building and Construction Commission made on 8 June 2018 to not issue a Direction to Rectify is confirmed.
CONTRACTS – BUILDING, ENGINEERING AND RELATED CONTRACTS – PERFORMANCE OF WORK – REMEDIES FOR BREACH OF CONTRACT – where an application for review of a decision to not issue a direction to rectify was made – where moisture was entering the edge of a house slab – whether the builder had placed fill against the edge of the slab – whether a builder is required to extend a membrane up the external edge of a waffle pod slab – where the Queensland Building and Construction Commission was urged to investigate moisture issues in relation to waffle pod slabs, and to issue consumer warnings, and to consider changes required to the Australian Standard and the Building Code of Australia
Australian Standard 2870
Building Code of Australia 2016 Vol 2
Queensland Building and Construction Commission Act 1991 (Qld), s 3(c)
S Nean (In-House Solicitor, QBCC)
REASONS FOR DECISION
- Ms Beikoff and Mr Beikoff (‘the owners’) contracted with Ownit Homes Pty Ltd (‘the builder’) on 21 July 2017 to build a new house at Helensvale in Queensland.
- The house was a single story slab on ground construction. The concrete slab was constructed using what is known as a ‘waffle pod’ method, which involves the use of polystyrene foam blocks to act as forms on the ground.
- The house was handed over to the owners by the builder on 22 February 2018.
- The owners carried out landscaping works on 16 March 2018.
- On 8 May 2018 the Ms Beikoff contacted the builder by email about rising damp and efflorescence which she observed on the concrete in the garage of the property and the store room area.
- The owners made a complaint to the Queensland Building and Construction Commission (‘QBCC’) on 8 June 2018 in respect of the rising damp.
- The QBCC made a decision not to issue a Direction to Rectify to the builder on 24 September 2018. The owners made an application to the QBCC for an internal review of that decision on 7 October 2018.
- The QBCC made an internal review decision on 31 October 2018 not to issue a Direction to Rectify.
- The owners filed an application to review a decision, in relation to the decision of the QBCC made on 31 October 2018.
- The matter was heard by oral hearing on 21 October 2019 and 27 November 2019. At the conclusion of the hearing I gave directions for the filing of submissions. The submissions were received by 31 January 2020. The matter was subsequently referred for a decision.
- This is the decision in relation to the Application to Review a Decision.
Nature of the dispute
- The use of waffle pods is widespread in the Queensland residential construction industry. There are advantages in cost saving in labour and time in using this method. Waffle pod slabs sit on top of the ground. They have particular application where building on well-compacted flat sites which have good drainage away from the building in all directions. The method replaces the traditional method of using bedding sand and in-ground footings to form a slab.
- This matter concerns the absence of a membrane as a vapour barrier to protect the edge of the slab from water intrusion.
- The essence of the owners’ claim is that the builder did not provide a membrane that did this, and placed fill against the edge of the slab and that, as a result, water has entered the slab which is porous, and moisture has risen from there.
- The essence of the builder’s position is that it was not required by any relevant Australian Standard, or similar regulatory provision, to provide such a vapour barrier in the case of a waffle pod construction, and that the problems have arisen because the owners placed fill against the edge of the slab in the course of landscaping.
- There are factual disputes as to who placed fill material against the edge of the slab:
- (a)The builder had a contractor conduct a final tidy up and levelling before handover. There are questions as to the extent of that work and whether fill was moved by that contractor.
- (b)The builder says that the owners extensively filled beside the house in the course of landscaping works, and in doing so did not insert a membrane against the edge of the slab.
- (c)The owners say that they only spread a very thin layer of topsoil when turfing beside the house.
- (d)The owners engaged a pest contractor to insert a perimeter termite barrier system of permeable piping, and questions arise as to when fill was placed over that system, as to how much fill was placed, and as to who placed that fill.
- (e)A possibility is suggested that the builder or landscaper of the adjoining block may have pushed fill onto the owners’ block.
Complaint to QBCC
- Ms Beikoff stated that approximately 10 weeks after occupancy of the dwelling and moderate rainfall, she and her husband observed efflorescence and rising damp in the garage area and storeroom area of the residence.
- The builder engaged Morgan Consulting Engineers, who had done the structural design of the building in 2017, to inspect the reported water ingress. They carried out a walkover inspection on 14 May 2018, and an invasive inspection on 29 May 2018.
They noted the following matters on their inspection:
The ground around much of the residence was near level and poorly drained. The ground along the western side of the garage sloped away from the residence (photograph 2). During the invasive investigation a small excavation was carried out along this side of the driveway. This investigation revealed that the soil was in direct contact with the slab and that the plastic vapour barrier protruded a short distance from the edge of the slab (photograph 3). Moisture meter readings indicated a moisture content in the slab edge of approximately 23%.
Discolouration was also noted to the rendered slab edge along the rear patio. Efflorescence and mineral deposits were noted along a line that appeared to correlate with the base of the tiles (photographs 4 and 5). Moisture meter readings indicated elevated moisture along this line compared to the remainder of the slab edge.
2 .3 Internal
The interior of the residence was generally in good condition. Evidence of moisture and efflorescence was noted along the western wall of the garage (photographs 6 and 7). The extent of wetting along the edge of the garage had reduced by the time of our follow-up inspection. Moisture meter readings found the moisture content along this edge of the slab to be approximately 23%, while the moisture content toward the centre of the wall was approximately 13%.
During the invasive investigation a hole was cut in the plasterboard linings of the western wall of the garage in an area where the slab edge was wet. This investigation revealed that the timber framing, ply bracing, brickwork and sarking on the wall cavity were all dry (photographs 8 and 9). Moisture meter readings of the various materials very [sic] between 10 – 15%.
Inspection of the storage room under the stairs on the eastern side of the residence found a slight discolouration along the edge of the slab (photograph 10). A sealant had been applied along the base of the doorframe (photograph 11). Moisture meter readings showed that the moisture level was consistent internally and along the edges, with readings of approximately 11 – 13%
- The owners made a complaint to the QBCC on 8 June 2018, and a QBCC building inspector, Mr Steve Jeynes, inspected the premises on 21 August 2018, and reported as to the damage:
A visual inspection was undertaken to the garage floor and surrounding building, which revealed:
There was evidence of minor rising damp and efflorescence to the garage floor adjacent the side wall (Western side external wall) and to the storeroom (eastern side)
It should be noted that the garage/storeroom is a non-–habitable area under the Building Code of Australia. There was no evidence of moisture damage internally to the remainder of the house.
- Mr Jeynes noted the extent of the vapour barrier as follows:
The underslab damp proof course (plastic vapour barrier) protruded a short distance from the outer edge of the slab/footing. This system is in accordance with AS 2780 residential slabs and footings (vapour barrier may terminate here with local acceptance (see clause 5.3.3(b)). There was no DPC between the edge of the slab/footing and the landscape soil.
- Mr Jeynes concluded that it was not appropriate to issue a Direction to Rectify:
Item 1 of your complaint form has been investigated and there was insufficient evidence to reveal any obvious defective construction practices by Ownit Homes Pty Ltd at the time of inspection. It is not considered fair or reasonable under the QBCC Board Policy to send the Licensee a direction at this time.
- The owners applied for an internal review of the decision of Mr Jeynes. The internal review officer obtained further technical advice from Mr Steven Noble, QBCC Senior Technical Internal Review Officer.
- Mr Noble provided an ‘Internal Review Desktop Report’ dated 29 October 2018. He noted that he was satisfied that the BCA 2016 Vol 2 was the appropriate code to assess the construction works in dispute, and that the Rectification of Building Work Policy which applied was that of 10 October 2014.
- Mr Noble described the situation in relation to the vapour barrier as follows:
The polyethylene vapour barrier appears to have been installed below the waffle slab, and surplus vapour barrier is visible to the front right-hand side elevation of the garage through review of photos in QBCC archives.
However, in review of the photos, surplus vapour barrier is not evident along the right-hand side of the garage. Interestingly, efflorescence is visible along the internal garage slab along this elevation. Mr Jeynes has confirmed through visual inspection of an existing wall vent that the garage structural frame along this wall is dry and no sign of deterioration despite evidence of slab edge dampness manifesting as efflorescence.
While it is appreciated that invasive investigation may provide a clear understanding of the extent to which the slab edge dampness has affected the structural frame, it is reasonable to conclude that the underlying issue is the absence of the vapour barrier extending above the finished ground to this elevation.
- Mr Noble noted that other parties undertook the landscaping, and that it was the responsibility of the persons undertaking those works to ensure that the requisite standards of AS 2870 were not contravened:
Of particular interest is that other parties undertook the landscaping. Prior to the landscaping works commencing, the finished ground level was approximately 150mm below the slab edge rebate, or 150mm below the weep holes to the masonry veneer. The landscaping works completed after this has reduced this margin. Please refer to the pictures provided below by way of comparison.
Prior to undertaking the landscaping works, the responsible party undertaking the proposed works must first confirm that the preceding works is fit for purpose, and that proceeding with the landscaping will not contravene requisite standards of AS 2870.
When parties ascertain that proceeding with landscaping will result in contravention of Australian Standards, it is incumbent on them to notify the respective parties and seek remediation of the issue prior to commencing with the landscaping works.
- Mr Noble found that it was not possible to apportion responsibility for the noncompliance with AS 2870:
While it is acknowledged that the vapour barrier detailing to the right hand side of the garage does not comply with AS 2870, apportioning sole responsibility is not possible where two separate parties have undertaken works within the same location.
Subject to the evidence at my disposal, I cannot determine beyond reasonable doubt who caused the slab edge dampness to the garage external wall.
- The Internal Review Officer relied upon the report of Mr Noble, and concluded that a
Direction to Rectify should not be issued:
In the circumstances where the applicant has performed landscaping works and changed the finished ground level around the property, I cannot be reasonably satisfied that the defect is the sole responsibility of the affected party.
For this reason, I have decided not to issue a direction to rectify for item 1.
- Sections of the Australian Standard 2870 – 2011 Residential slabs and footings (AS 2870) and the National Construction Code Building Code of Australia (BCA/NCC) are relevant. The object of AS 2870 is to ‘specify performance criteria and specific designs for footing systems for foundation conditions commonly found in
- The following sections of AS 2870 (5.3.3 Vapour barriers and damp–proofing membranes) are relevant:
Where required, the raft or slab shall be provided with a vapour barrier, or a damp – proofing membrane.
Both vapour barriers and damp–proofing membranes shall be installed as follows:
- (a)The sheet shall be placed beneath the slab so that the bottom surface of the slab and beams, including internal beams, is entirely underlaid. The membrane shall extend under the edge beam to ground level; however, where justified by satisfactory local experience, a vapour barrier may be terminated at the internal face of external beams as shown on figure 5.2(a)
- (b)Lapping for continuity at joints shall be not less than 200mm
- (c)penetrations by pipes or plumbing fittings shall be taped to or sealed with a close – fitting sleeve or made continuous with the vapour barrier or damp – proof membrane by taping or by lapping in accordance with item (b)
- Functional statement F2.2.2 provides that ‘a building is to be constructed to provide resistance to moisture from the outside and moisture rising from the ground’.
- The following sections of part 2.2 of the BCA/NCC, which deal with damp and weatherproofing, are relevant:
184.108.40.206 Vapour barriers
A vapour barrier must be installed under slab-on-ground construction for all class 1 buildings and for class 10 buildings where the slab is continuous with the slab of a class 1 building as follows –
- [c]The vapour barrier must be placed beneath the slab so that the bottom surface of the slab is entirely underlaid and extends under edge beams to finish at ground level in accordance with Figure 220.127.116.11
The owners’ evidence and submissions
- Ms Beikoff gave evidence that her property was affected by rising damp. She said that she first noticed discolouration on the floor along the western side in the garage where there was just concrete, and after a few days there was actually a sign of efflorescence following the outline of that discoloration on 8 May 2018. She said that the efflorescence was notable in the storage area on the eastern side a couple of weeks later.
- Ms Beikoff was asked about the site clean-up conducted by the builder, and said that it was done on 31 January 2018 by Damo’s Diggers Proprietary Limited who were engaged by the builder:
Okay. Can you tell me about the site clean-up? – – We were – this was about three weeks before handover and we were on site and a bloke turned up with a bobcat, and he actually asked us if we wanted to keep any of the bricks that were lying around the place, because he was doing the final clean up, and there was – he was moving a stockpile of dirt around that clean-up. So yeah, I was there for that.
- Ms Beikoff said that she saw the bobcat driver moving dirt around near the slab:
Okay. Did you observe the bobcat driver to fold up any Visqueen barrier around the slab prior to moving the dirt around with the bobcat? – – No.
Okay. Did you observe the bobcat driver to install any further Visqueen barrier to prevent dirt being moved up and contacting the slab? – – No.
And when the bobcat driver moved dirt around, was it near the slab at all? – – Yes.
- Ms Beikoff said that landscaping was done on 16 March by herself, her husband Geoffrey, and Dan Arnott, and said that she did not see or touch any vapour barrier:
Alright. When the landscaping was undertaken, did you see any vapour barrier around the slab before you commenced landscaping? – – No.
Did you cut or remove any vapour barrier from around the slab during landscaping? – – No.
Did you fold down any vapour barrier from around the slab during landscaping? – – No.
Are you aware if you’d covered any vapour barrier with soil so that the soil would come into – fold the vapour barrier down, the soil would come into contact with the slab? – – No.
- Ms Beikoff said that they had additional termite protection installed after the build. She looked at photographs, and said they showed the termite reticulation piping run around the concrete edge, sitting on top of the ground level against the slab, and could not see any Visqueen barrier in the photograph.
- In cross examination Ms Beikoff was asked about the grading of the soil that was done for the landscaping, and said that they followed what was done by the builder:
And you complied with that by building up the ground to make sure it sloped away?… No, the – there was already soil up against the house and there was – it was fairly high against the house as it was, so – and we were reaching down to where the neighbour was because theirs had already been done. So we couldn’t go any higher because the slope was marginally – it’s more than 150 mil drop there, so…
Sorry, you said that you ensured that you complied. How did you ensure that you complied?… We drained away from it. We were actually told that by Ownit Homes, to make sure that we graded away from the house.
Yes, but how did you achieve the grading?… We used the ground level that was there at handover, and we used the next door neighbours [sic] final landscaping, because they had finished it before us, and – so we just pretty well-kept it the same.
You kept it the same?… We did put some topsoil over it.
Yes?… Yes, but we couldn’t change it very much, because it was too high as it was.
- In relation to material placed against the edge of the slab, Ms Beikoff was asked how much topsoil was spread under the turf, and agreed that they placed about 35 mm of soil in total against the edge of the slab.
- She said that she was not able to state how much fill the bobcat driver had placed against the edge of the slab:
Do you have any idea what depth of fill the bobcat driver, prior to handover placed against the edge of the slab?….No. I couldn’t be definite in that. I do know that, on that Western side, the slope was pretty steep, because it was difficult even just walking down there, so it was pretty steep to begin with, and you can see that in the photographs. I do know the bobcat driver didn’t place a lot at the back because there was a lot of – it was a low-lying area, and, as you can see in those photographs, there is water lying around.
Did you observe what the bobcat driver was doing there on 31 January 2018?… Just-he cleaned up the site of bricks and everything, and then he just moved the stockpile and was just pushing up against the house. I don’t think he made any effort to fill any lower areas. He just pushed up against the house.
But you’re not able to estimate the depth of fill that was placed by the bobcat driver, I think you said?… Yeah, I would be guessing.
Against the edge of the slab?… I would be guessing.
- She said she had been given only limited instructions as to how to conduct landscaping by the builder:
Did you receive any instructions from the builder as to conduct of landscaping works after handover?… I was just told by the – our supervisor to ensure that all landscaping sloped away from the house.
Sloped away?… Here, and not to cover the inspection outlets for the sewerage, which was – I think we have two.
- Mr Daniel Arnott assisted with the landscaping work. He said that he was aware at the time that the ground is not supposed to be above the vapour barrier, that he did not see any vapour barrier, but proceeded with the landscaping by following the existing gradient, and that the thickness of the layer of topsoil they spread would have been ‘not even an inch’.
- Mr Geoffrey Beikoff said that he observed a bobcat clean-up around the perimeter of the housing block as follows:
And can you describe to me what you observed to take place with that site cleanup? What happened?….It was primarily a bobcat cleanup around the perimeter of the housing block
And what did the bobcat do?… He moved scrap – he moves soil – he removed heavy bulk bricks and stuff away from the site, while also distributing soil up against the side of the house.
- Mr Beikoff said that he did not see any vapour barrier before he commenced the landscaping.
- In relation to termite control, Mr Beikoff said that there were two types of control, one that the builder put in, and one that was put in as a reticulation system around the perimeter of the house afterwards, probably two days after handover at the end of February or the beginning of March 2018. He described the termite conduit as sitting slightly exposed on top of the ground on the western side near the corner of the garage, on 24 May after the landscaping was done.
- Mr Beikoff was asked in cross examination about the landscaping work done by the neighbour and said it was done before he did his landscaping:
And just to clarify something that I think was a bit new in your evidence-inChief, but I don’t think is in your statement, but correct me if I’m wrong. Subsequent to this photo being taken, but before you did the landscaping, the neighbouring property did landscaping. Is that correct?… That’s correct.
And that’s when the fence was installed, also?… Yeah, about the same-yes.
Okay. So is it possible that the – the neighbouring – the neighbours [sic] landscape affected this at all? Because when I look at this, and this, it’s a bit different and I apologise for putting you on the spot, but I hadn’t seen any evidence about the neighbours [sic] landscaping until – until today?… The same landscaper did their site, the fence on our side. Not the landscaping on our site. It is possible but maybe unlikely.
The commission’s evidence and submissions
- Mr Bradley Ganim, the managing director of Ownit Homes, gave evidence. He said that he did not believe that any dirt was spread by the bobcat in the course of the site clean-up as there was no dirt on site.
- I asked Mr Ganim to describe the usual practice of his company, and he said it was to extend Visqueen from the bottom of a waffle pod slab:
Mr Ganim, on the plans for this contract, is there anywhere that you see a foundation design plan that shows the extent (indistinct) of the (indistinct) barrier on the outside of the slab?….Sorry, in one of our details, it shows that we put the Visqueen down and turn it up.
Yes. Is there anything noted on the plan as to the extent that the Visqueen has been turned up on the outside of the slab?… Not that I’m aware of.
All right. Would that be the usual practice, for your company to provide for Visqueen to extend out so the bottom of the slab to turn up to come to ground level?… Yes. More so, in particular, if we’re doing the landscaping.
You know Mr Ian Dennis?… Yes
He is the construction manager for your company, is he?… That’s correct.
And he was a construction manager on this job?….Yes, he was.
All right. I’d like you to look at the statement of reasons (indistinct) tab 2, page 156. Now, at that page, there is an email from Mr Dennis to the Beikoffs dated 17 May 2018. And in the last large paragraph it says:
What Mark was actually making comment on was the plastic Visqueen that is laid under the slab is fitted. When the concrete sits up to place the slab, this plastic sheet is laid down on top of his bedding sand and before the pod is fitted. This is allowed to hang outside the formwork, across the ground, and there is sufficient sitting external of the slab edge that allows for it to be turned up the edge of the slab, before any filler is placed against the slab edge itself. This is to prevent any moisture from the – within the soils or fill to suck back through the slab edge.
Would you agree that’s the usual practice?… Yes.
- Mr Ganim said that he was unable to see any Visqueen extending from the bottom of the slab in the photographs shown to him:
Do you have any evidence that the Visqueen was laid out as described by Mr Dennis in that email on this job?… Not that I can see.
Have you seen any photograph that shows the Visqueen extending at the bottom of the slab sufficient to be able to fold it up to ground level?… Not in any photos I’ve seen.
- Mr Ganim said that the side of the slab would have been 150 millimetres high:
Well, that’s the plan. I’m more interested in the as constructed?… Well, that’s a standard profile that the concreters have. That’d be 150, that side of the slab.
So you think – you think that side of the slab would have been 150 from the plans, but you – can you in any way assess whether it actually is, as constructed, 150?… It would have to be for the engineer to pass it. It’s a standard bracket the concreters have. It has a 150 millimetre stand up, and that’s the standard sizing for – for waffle pods.
- Mr Ganim said that he was present when his maintenance man dug a hole beside the slab, and that he did not observe any Visqueen extending from the slab, but that it seemed that the Visqueen had been torn, and he doubted that was done by the bobcat driver:
Now, you say you dug that hole as shown in photograph 3. Did you break off any of the Visqueen, or observe that the Visqueen extended any further than just under the bottom edge of the slab, as it seems?… That’s the unknown.
That’s the only?… That’s the unknown.
Well, when you dug down, did you find anywhere that the Visqueen was turned up to ground level?… No, I did not.
All right?… But you could see it looks like it’s been cut or something’s happened – well, there is a section on that just to the left of that straight section that looks like it’s torn.
Right?… But that’s – that’s the unknown, I suppose.
Yes. Could the Visqueen have been torn by the cleanup bobcat driver, as he was cleaning the site?… I doubt that because it’s the access down that side. I can’t – you know, the access down the side so – you’ve got to make – the machine can get down the side there.
-  Mr Ganim described the fill which he saw in the hole beside the slab:
Now, when you excavated, that hole, as shown in photograph three, if the situation was that there had been fill placed next to it you’d expect to see different stratas of fill – different layers of material. Did you find different layers of material as you dug that hole? – It’s hard to recollect, but looking at the photos there it looks like there’s another product there, like, it’s a loosey, grainy type material.
Yes, it does. Could that be decomposed granite?… Cannot comment.
Is it the sort of material the concreter may have used as a base of the foundations to fill under the waffle pod as you were referring to earlier?… I don’t know. I can’t make that assumption. It could also be fill the clients brought in to get the land, you know, build the land levels up.
Did you find topsoil?… Can’t really remember, but I assume so because we had there – got some grass.
But in the layers – because essentially this photograph might tell the whole story because it’s when you dug, it shows no Visqueen up the side, it doesn’t seem to show any substantial layer of topsoil, unless you can point it out. What it seems to show is a consistent layer of another material which hasn’t been identified. It might be broken concrete, it looks like there’s lumps of concrete in the bottom there, some sort of granular material. But the suggestion is that the homeowners in the landscaping process have filled above the level that proper construction would have taken to, which is that ground-level. Is there any evidence of that in that photo – of landscaping activity filling?… It is certainly some sort of fill the – looks to be there.
Some sort of fill, but the evidence of…?… It could come you know it could have come from anywhere. It could have come from even the neighbours [sic] fence being dug when they dig those holes that, and they put that there as well. It’s too hard to say. It’s – there’s no definite answer. But what we can see on photo A – there’s nothing really there at the time of slab.
Do know what the finished level should have been at handover when you look at that photograph? At what point on the…?… Well, you could also assume – sorry, Member – that if that – if you’re – what you’re alluding to a little bit – I mean, it’s an assumption that that could be the crusher dust from the concrete.
Well, that was a question I asked?… Yeah. Oh, right. While it would be there at time of slab too. So doesn’t look to be there are time of slab, and there is no – no residue of it around, but you can see from the photos. So I’d say that it’s come in at a later date, looking at the photos.
-  Mr Ganim was asked what he considered to be ‘ground level’, and said that he considered it to be the bottom of the slab:
Member: Well, where’s ground level shown on the plan you’re referring to? On page 87 of the plans. At page 87.
Ms Nean: Is that – Mr Ganim, is that straight line with the 385 goes to, is that ground-level?… Yes, it is. And just to elaborate, you’ll have an RL. I’m just trying to find that. And that would be – the note says ground-level to, which will show 385 mil below the slab, which will be the RL on document 77 of the plans. I haven’t got the. It’s approximate pad level and slab level. So the pad level is 4050, which would denote as ground-level. In the slab level is 4435, which is slab level, approximately, which is in the centre of the drawing. So from your question, I am saying ground-level is 4050, which is the pad – which is the pad level, which is where we cut the site.
Member: the plan you’re referring to at page 77, Mr Ganim, is the earthworks plan. It’s the site scrape?… That’s the ground level.
Well, that’s not the finished ground level?… I don’t know what the finished ground level is, though, when I handed over the job. I’ll have no idea.
But that’s the whole point of this. This is about the vapour barrier going to the finished ground level?… But that’s not my – you can even see on this diagram here, you can even see some of the slab exposed. I don’t know. That wasn’t part of my obligation to do any external works and there are systems and methods you can do to protect the side of the slab. So when I – you know, from the photos, from what I’ve ascertained, we’ve handed the house over at the ground level, which is that pallet, which is the site scrape, which is that pad level.
- Mr Steven Noble, the Senior Internal Technical Review Officer for the QBCC, gave evidence, and referred to the engineer’s drawings for the construction:
A:… So this – this provides that the engineer had required that that vapour barrier extend under the whole of the slab itself. And that it terminated outside that external edge of the slab and not inside the internal edge of that slab.
Q: And it doesn’t show the barrier terminating any specific distance up the side of the – the – side of the slab?
A: No. It doesn’t show it extending vertically whatsoever. It just – it just denotes it is extending beyond the slab edge. Now, as discussed before, and I’ll – I’ll use of page – page – or annexure A, page 5 as an – a good way of indicating what construction has occurred here, is that the – if you look – if you reference that – that photo and then you look at the rib – edge rib section of this detail of which are talking about right now, it shows that inside that (indistinct) that edge is the waffle section that is provided inside that slab edge rebate. It also shows that that – that slab is situated on the top of ground. So in a – in a practical sense, when you are constructing this you would level the site to whatever – whatever that level height requirement is. You would then install your sand which should take into consideration any protruberances [sic] or deviations to that plan through the excavation process, and provide a reasonably flat workable finish that’s also quite soft. And then that vapour barrier would then be rolled out and lapped accordingly to the extent of that slab. And then on top of that would be the formwork which would then be sitting on top of that sand to form up the external slab edge rebates and the perimeter of that slab. And that’s what we’re looking at in this photo after the formwork has all been removed. And the – the slab is clearly sitting on the ground. On level ground upon which the building platform had been created for that.
- Mr Noble went on to describe why the vapour barrier just extends horizontally, because the slab sits on top of the ground:
… So the difference between that and the engineering design, because this is a waffle pad, is that this slab has not been designed to be excavated into the ground level itself. Rather, it sits on the top and so that vapour barrier doesn’t need to extend down into a thickening beam within the ground. This vapour barrier just extends horizontally to the full platform of the building.
- I asked Mr Noble what he considered acceptable building practice was as to the extent of the extension of the Visqueen, and he said that extending to the bottom of the slab was acceptable, as follows:
So your view is that it’s acceptable for the builder to have only extended the membrane to the bottom of the slab as shown in photograph 3 on the Morgan report?… The engineering design required that the membrane terminates there, and it’s also a requirement that there is fall from that particular point outside of that slab to the entire perimeter.
That wasn’t my question. My question was what, in your view, was an acceptable building practice for the builder. If we look at photographs 3 of the Morgan report, it looks like the membrane is extended to the bottom of the slab.
Do you consider that the proper building practice?… Yes.
All right. Well, in that case, let’s stay on photograph 3. The question then becomes that somebody has piled material above the bottom of the slab, up the slab edge without there being a membrane running vertically. So that then becomes a problem, that somebody has done that?… Yeah, somebody has done that.
- Mr Noble said that he was unable to say who placed the fill material that was observable in the excavation beside the slab:
All right. So, we still keep coming back to the material that is shown in photograph 3 of the Morgan report. And this becomes probably the central question then, who has placed that material there?… Yes, so this is the question that I’m not able to provide.
All right. That if we…?… And hand on heart I cannot say that it was placed by the owners or placed by the builder. On the material, it’s a timeline and it’s on the photos during the course of the construction that I’m looking at as well as the works, or the subsequent photos, that I’m able to look at. That’s all I can see. What the landscaper did, who – whether that materials been pushed from an adjacent lot across, I’ve got no idea.
- Mr Noble was asked if it was possible that the neighbour may have pushed some gravel material from their site, and he thought that was possible:
We can see in the excavation that there’s got to be a fair suggestion that material may have come from that pile on the adjoining site but if that adjoining house was finished earlier that cleanup of that site has pushed some of the gravel material onto Beikoffs’ site. So, it’s something that hasn’t been done by this builder or by the Beikoffs but perhaps by the neighbour?… It’s – that’s possible that that’s the case.
- He then referred to some photographs and identified that a builder’s fence between the two adjoining construction sites was not actually on the boundary, and that fill may not have been contained on the neighbour’s site from the construction:
So, well inside the temporary fencing?… Yes. So the temporary fencing has been put onto that site by Orbit Homes when, in actual fact, that’s not the boundary. The boundary sits further inside that.
Sorry, you mentioned Orbit Homes, which side are they building?
Right?… That has been placed not on this site but on – actually on the adjoining site.
So it’s encroaching on the adjoining site?… It’s encroaching on the other side. There’s a whole lot of timber that you can see there is well which – Clearly the builder is using it during the course of the construction
Right?….But that fence is on the adjoining site. So when they commenced building that adjoining site, which is where that red car is poking out of the – that fenceline would no longer be there, it would be further across towards a building. So, it is feasible in further reflection that some of that material may have come from the adjoining site because that clearly – the material that’s been placed there is clearly in the middle of where the slab would be, that – it’s where that house currently is, is where that material is. And that would need to be spread by machine in order to provide a level building platform, I imagine that’s what they’re using it for. And it is possible that that can encroach on this particular site that we’re talking about today.
- This matter raises significant questions about issues related to the use of waffle pods.
- It is clear that the house has been affected by moisture intrusion which is occurring because soil has been piled against the unprotected edge of the slab, and water has moved from the soil into the slab edge which is porous.
- The question is as to who placed the soil against the edge of the slab, and whether there should have been a moisture barrier placed by the builder against the edge of the slab to prevent moisture seeping into it.
- The QBCC declined to issue a Direction to Rectify in the first instance, because the inspector, Mr Jeynes, concluded that there was insufficient evidence to reveal any obvious defective construction practices by the builder, and that it was considered not fair or reasonable under the QBCC Board policy to give the builder a direction at that time.
- An internal review by the QBCC confirmed that decision. The internal reviewer sought advice from Mr Noble, the QBCC Senior Technical Internal Review Officer. Mr Noble expressed the view that it was not possible to determine who conducted works without a vapour barrier being present, and referred to ‘two separate parties who had undertaken works within the same location’.
- Mr Noble was referring to the alternatives that either the builder had placed soil against the unprotected side of the slab; or that the owners had done so when they placed topsoil and turf beside the house.
- The owners steadfastly refused to accept that they had placed any significant quantity of soil against the side of the slab, and pointed to cleanup works conducted by a bobcat operator contracted by the builder as having piled soil against the side of the slab.
- The owners did not obtain independent engineering advice, and relied upon their personal observations.
- After the owners complained of water intrusion, the builder had an engineering firm, Morgan Consulting Engineers, conduct investigations. Mr Ganim, the principal of the builder, described his being present when a hole was dug by the engineer against the side of the slab.
- A photograph of the excavation appears at page 98 of the QBCC statement of reasons. In my view, that photograph is the key to understanding this matter, and reveals the mechanisms at play. The photograph shows:
- (a)the bottom of the slab with Visqueen visible at the bottom edge of the slab, but not extending up the side of the slab at all;
- (b)a deep layer of material that is a loose grainy material;
- (c)a thin top layer of topsoil with grass on it.
- I am satisfied that the builder extended a plastic membrane (Visqueen) under the slab, which extended to the edge of the slab.
- I accept the evidence of the builder that the works conducted by the contractor with a bobcat would have been minimal, as a site cleanup, to scrape the site clean, but not to place or move any significant quantities of fill.
- I am satisfied that the builder’s contractor did not place any substantial amounts of fill against the side of the slab.
- There is no evidence of any large quantities of topsoil being purchased, or spread by the owners. I accept the evidence of the owners, and a person who assisted them in laying topsoil and turf, that they did not place any significant depth of topsoil below the turf.
- I am satisfied that the owners did not place any substantial amounts of topsoil against the edge of the slab.
- Where then, did the deep layer of loose grainy material which is shown in the photograph, and which is placed against the side of the slab, come from?
- In the course of the hearing, and particularly in the course of the evidence of Mr Noble, two further possibilities emerged as to the source of the fill:
- (a)the fill may have been pushed from the adjacent block, where a house was being constructed at a similar time; or
- (b)the fill may have been placed by a termite control contractor engaged by the owners, after the house was handed over, to install a further system of plastic piping to distribute a termicide chemical.
- No clear evidence was obtained as to what works were performed in relation to the adjoining block. The owners however referred to a landscaper working on the adjoining block, and to levels between the two blocks which differed at times, and the erection of a dividing fence.
- Photographs were put in evidence of the owners’ house during construction which showed a temporary construction fence put in place by the builder of the adjoining house. Mr Noble’s evidence was that the temporary fence was not on the proper boundary line, and encroached upon the adjoining block. There was therefore clearly an overlap of activity between the two blocks.
- The dividing fence was built after the builder had handed over the house. The builder suggested that it may have required the digging of holes for the fence posts, which would have produced a quantity of fill.
- In his evidence, Mr Noble described, as quoted previously, that he considered that it was feasible ‘in further reflection’ that some of the material may have come from the adjoining site which would have been spread by machine in order to provide a level building platform, and it was possible that it could encroach on the owners’ site.
- Mr Noble said that the practice of a termite control company would be that generally they don’t undertake landscaping works, but they are required to ensure that the system was concealed before being charged chemically, so that it was safe to then charge with the termite management product used – otherwise they would be risking
the safety of anybody who may frequent that section of the building where it was being installed.
- He went on to say that traditionally the termite system would be covered with a pavement of sorts, to avoid chemical leaching occurring with someone barefoot, for example, who could walk over it and ingest it.
- There is then a possibility that the termite control company may have placed soil over the termite system. Mr Noble’s evidence was that the reticulation system needs to be below the surface in order to satisfy the requirement of chemically treating soil, but he did not indicate that a deep excavation was required, which would entail large amounts of fill being placed over it and against the edge of the slab.
- I consider it unlikely that the termite control company would have moved significant quantities of fill, as there is no observation of that, and no specification in a contract with that company for any such work.
- I consider that the most likely source of the fill being placed against the slab edge was by the adjoining builder, or landscaper, pushing fill between the two blocks to create final levels in preparation for, and in the course of construction of, the boundary fence.
- Whilst it cannot be established with certainty as to how the loose grainy material came to be placed against the edge of the slab of the house, I am satisfied that it was not done by either the builder or the owners.
- The cause of the moisture rising up the walls of the house, which is the owners’ concern, is the absence of a waterproof membrane of any sort along the edge of the slab. The question then becomes – was it the responsibility of the builder to have placed a membrane along the edge of the slab before handing the building over?
- Mr Noble discussed the engineering design which was provided to the builder, which only required that the vapour barrier terminate at the external edge of the slab:
Mr Noble:… So this is the – this is the approved engineering design for which Morgan Engineering has prescribed the method of construction for the builder. The dotted line here is denoted as being the vapour barrier. And this can be evidence [sic] through the diagram and what is classed as the internal rib section. And you’ll see there is a note there, the vapour barrier on 50 mil of sand bedding. And it points to the dotted line which denotes the – the vapour barrier installation. The reason why I’m pointing you to the internal rib section is obviously that is part of the vapour barrier that is required to be installed below the slab to the extent of the slab. And that dotted line is shown in the other diagrams, or detailing – engineering detailing on either side of that. In that instance, you’ll note that the vapour barrier on either side of that you’ve got the widened edge rib section. It shows that same dotted line. It shows that dotted line extending beyond that slab edge rebate. On the left-hand side the edge rib section, again it denotes that same dotted line. And it shows that line extending beyond the edge of the rebate.
So this – this provides that the engineer had required that that vapour barrier extend under the whole of the slab itself, and that it terminated outside that external edge of the slab and not inside the internal edge of that slab.
Ms Nean: And it doesn’t show the barrier terminating any specific distance up the side of the – the – side of the slab?
Mr Noble: No. It doesn’t show it extending vertically whatsoever. It just – it just denotes it as extending beyond the slab edge.
- The situation has arisen because of the particular use of a waffle pod slab. Extensive regard has been had in the course of the hearing to the Australian Standard in relation to the placing of membranes generally in slab construction.
- The Australian Standard addresses the traditional methods of foundation slab construction by requiring a membrane to stop moisture moving into the slab. The diagrams that are illustrated in the Australian Standard are predicated upon a traditional in-ground footing. They show a membrane extending up to a finished ground level, or an internal membrane that extends above the height of finished ground level, which prevents moisture passing through the slab edge.
- The singular characteristic of a waffle pod slab is that it sits on top of the ground. The builder has given evidence that the requirement was to only extend the Visqueen (the plastic sheet which acts a membrane) to the edge of the bottom of the slab, as that is the height at which it handed over the property in this instance, as no landscaping was included in the contract.
- Mr Noble in his statement identified that the relevant Standards and Codes only require that the vapour barrier extend to ground level:
Neither AS 2870 nor the National Construction Code or the Building Code of Australia prescribe an amount which the vapour barrier must extend past ground level. The requirement is that the vapour barrier extend to ground level.
- Diagram (b) of AS 2870 (18.104.22.168) shows the internal membrane extending above the ‘finished ground including paving’.
- From the builder’s viewpoint, the ‘ground level’ which is referred to in AS 2870 (22.214.171.124) is the level of the bottom of the slab to which the surrounding ground was scraped, and at which the building was handed over.
- To an owner, the ‘ground level’ may be thought by them to be the ultimate anticipated level after the landscaping, which is the finished ground level shown in diagram (b) of that Standard.
- In the absence of any requirement in the engineering design for the building, or any provision as to landscaping in the contract, however, the ground level is the level of the base of the slab in the case of a waffle pod construction, as was used in this building.
- The builder and Mr Noble gave evidence that there are a number of edge treatment methods that could be adopted if it was desired to subsequently pile soil against the side of the slab, which would act to prevent moisture passing into the slab.
- I accept the evidence of Mr Noble which I have referred to in these Reasons.
- In the context of the engineer’s design and the Australian Standard and the Building Code of Australia then, the builder has complied with the requirements as to placement of an under slab membrane to the waffle pod construction.
- As I am not satisfied that the builder placed the fill against the side of the slab, and as the builder did not contravene the engineer’s design for the slab, or the Australian Standard, or the Building Code of Australia, as to extending the membrane up the external edge of the waffle pod slab, then a basis to give a Direction to Rectify is not made out.
The waffle pod system
- I consider that this matter has highlighted a significant issue of concern to consumers in relation to the use of waffle pod construction.
- It is striking that the Australian Standards do not specifically deal with this very common method of slab construction.
- I asked Mr Noble about Australian Standard AS 2870, as to whether there are any specific references to waffle pod construction, and he advised there were not:
Member: … Mr Noble, let’s get back to where we started, then. Let’s get back to the Australian Standard AS 2870. You will find that at…?
Mr Noble:… Sure.
Member:… Red letter 49 of the – of your statement?
Mr Noble: Yeah. Okay. Sure.
Member: Now, for the discussion, there’s three typical diagrams there. In the discussion we just had, does any of those relate to a waffle pod construction?
Mr Noble:… No. None of those do. The – the (b) of the deep edge rebate alternative is – is what you’re talking about. That’s not a deep rebate alternative.
Member: Okay. So…?
Mr Noble: Because it’s not a rather large rebate, if you like, for which…
Member: So can you point to any provision of the Australian Standard or the Building Code that refers to a required damp-proof membrane for a waffle pod construction?
Mr Noble: No.
Member: And that might be our problem?
Mr Noble: The – I only point to the requirements for the termination of the vapour membrane.
- Ms Beikoff said that the only instructions as to landscaping she received from the builder was from the supervisor, who said to ensure that all landscaping sloped away from the house, and not to cover the inspection outlets for the sewerage. That advice did not warn of the need to place a waterproof membrane along the edge of the slab, or to treat the edge of the slab, before placing soil against the edge of it.
- The Queensland Building and Construction Commission has a duty under section 3(c) of the Queensland Building and Construction Commission Act 1991 (Qld) to ‘provide support, education and advice for those who undertake building work and consumers’.
- When a consumer buys a house, as a subsequent purchaser, which has a traditional slab system, they can expect that the traditional practices of providing a waterproof membrane are in place to prevent water moving into the edge of the slab from any adjoining soil which is at the finished ground level.
- Once soil or gardens or turf is placed against the edge of a waffle pod slab, to the level of the top of the edge of the slab, and is blended into the surrounding area, it cannot be readily distinguished by a consumer from a traditional slab system, as it can no longer be observed to be sitting above the ground.
- Therefore, when a consumer buys a house, as a subsequent purchaser, which has a waffle pod slab system, and there is soil or gardens or turf in place against the full height of the edge of the house slab, the consumer has no ready way of observing that the slab has in fact been constructed with a waffle pod system, or whether a membrane or treatment to prevent water entry has been placed along the edge of the slab or not. I consider this to be a matter of risk and concern.
- I asked Mr Noble whether the situation is that a homeowner could be in the situation of having no protection, in the design of a waffle pod slab, against the effect of soil being placed against the unprotected edge of the slab, and water entering the slab, and that this seems to be a trap in the waffle pod design. Mr Noble responded that education for subcontractors and homeowners could be helpful in this regard:
Education around this could be helpful for subcontractors undertaking work, and education for homeowners could also be helpful. The commission does endeavour to do this through various information documents we provide on our, you know website, to try and assist in informing homeowners and also contractors of their obligations. However, it’s not perfect.
- I asked Mr Noble if he was aware of any similar problems arising with other waffle pod constructions, and he said that he was:
I am. I have another matter, which is down the coast, another recent matter, where fill material has been placed by a subcontractor against the – the slab to the perimeter of – of this particular dwelling, and it was causing significant moisture ingress. That was exacerbated by having a vinyl flooring system inside the house, which prevented that evaporating through the slab, causing mildew – so this is not uncommon, in my experience.
- I commented to Mr Noble that ‘You almost wonder why this doesn’t happen far more often?’ and he responded that it occurs more often than people are aware of:
I believe this has happened more often than people are aware of, through my observations on construction.
- I consider this is a situation which the Queensland Building and Construction Commission, in its consumer protection role, should investigate, and consider whether appropriate warnings should be provided to consumers, and whether the Australian Standard and other regulatory provisions should be amended to address the situation.
- I have found that it has not been established that the builder placed fill against the unprotected edge of the slab, and was not required by the Australian Standard, or other regulatory provision, to do anything further in relation to the edge of the slab of a waffle pod system, and therefore do not consider that a Direction to Rectify should be issued to it.
- I confirm the decision of the QBCC made on 31 October 2018 to not issue a Direction to Rectify to the builder.
- Having regard to the issues raised in this matter, I urge the Queensland Building and Construction Commission, in its role as a consumer protection agency, to:
- (a)investigate the prevalence of moisture problems arising in houses which have been built using the waffle pod system; and
- (b)give consideration to a need for builders of a new house with a waffle pod system to warn their customers that they should not place soil against the side of the slab without a waterproof membrane or edge treatment being provided; and
- (c)that there should be a way of a subsequent purchaser of a house being able to readily determine what slab system has been used, and whether an appropriate waterproofing system to the edge of the slab is in place if it is a waffle pod slab, before purchasing the house; and
- (d)give consideration to warning consumers who are the subsequent purchasers of a house, of the risks of buying a house with a waffle pod slab if the edge of the slab does not have a waterproof membrane, or treatment, between it and soil placed against it; and
- (e)consider whether the Australian Standard and the Building Code should be amended to specifically refer to waffle pod slabs; and if so, to make appropriate representations for amendment of the relevant Standard and Code to provide clarity and direction as to the placing of a membrane along the external edge, or for edge treatment, of a waffle pod slab.
 Affidavit of Angeline Beikoff dated 25 February 2019, Annexure A.
 Ibid .
 Ibid .
 Ibid .
 Ibid .
 Morgan Consulting Engineers’ Structural Inspection Report, 6 June 2018, p 2.
 Resolution Services’ Initial Inspection Report, 21 September 2018, p 4.
 Ibid, p. 4.
 Ibid, p. 4.
 Internal Review Desktop Report, 29 October 2018, p 1.
 Ibid, p 2.
 Ibid, p 2.
 Ibid, p 2.
 Decision Notice, 31 October 2018, p 2.
 AS 2870, p 2.
 Transcript 1-24, line 35.
 Transcript 1-26, line 19.
 Transcript 1-26, line 40.
 Transcript 1-27, line 23.
 Transcript 1-31, line 21.
 Transcript 1-41, line 15.
 Transcript 1-47, line 34.
 Transcript 1-47, line 37.
 Transcript 1-48, line 15.
 Transcript 1-48, line 20.
 Transcript 1-56, line 43.
 Transcript 1-63, line 1.
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 Transcript 1-64, line 10.
 Transcript 1-65, line 16.
 Transcript 1-77, line 44.
 Transcript 1-94, line 42.
 Transcript 1-101, line 39.
 Transcript 1-102, line 24.
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 Statement of Steven Noble, 11 July 2019, .
Transcript 2-32, line 41.
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- Published Case Name:
Beikoff v Queensland Building and Construction Commission
- Shortened Case Name:
Beikoff v Queensland Building and Construction Commission
 QCAT 377
Member Paratz AM
22 Sep 2020