Australia: NSW construction industry: Perspective of an expert on waterproofing and diagnostic reporting (part 2 of 6)

Last Updated: 29 May 2019
Article by Helen Kowal

Interview with Paul Ratcliff - Waterproofing and diagnostic reporting

Over the coming weeks, I will be releasing a six part article series. The articles will document my discussions with building consultants who are in the know when it comes to the current state of the NSW construction industry and the high percentage of properties which are found to contain building defects arising from original building works.

These experts will give their perspective on the current situation, the failings, the positives and their views as to what can be done to implement change and help builders, developers and consumers alike.

Presently, in place is the National Construction Code (NCC), implemented with a goal of achieving a 'nationally consistent, minimum necessary standard of relevant safety (including structural safety and safety from fire), health, amenity and sustainability objectives efficiently'.

There is apparent work to be done to achieve the goals of the NCC.

Paul Ratcliff - Paul Ratcliff Building and Waterproofing Pty Ltd

What is your area of expertise?

General building consultant specialising in waterproofing and diagnostic reporting.

How long have you been involved in the construction industry?

I entered the construction industry when I was 18 years old - so 39 years.

How long have you been providing expert witness reports in building claims?

For about 20-25 years.

With the NCC in place, in your opinion, why do you think there is still such a high rate of defective work arising out of residential construction in NSW?

That is an interesting question, there are a number of reasons.

First of all, I think the quality of building deteriorated when it went to private certification. In my view, certifiers are not taking on board their responsibility to properly inspect the work at critical stages. That is borne out in number of complaints in relation to waterproofing and internal wet areas, an area in which are still a high number of defects.

Secondly, I think there is an over reliance on performance requirements which are vague. I understand why performance requirements are in the hierarchy of the BCA, second to the section 18D statutory warranties (s18D Home Building Act 1989), but, I don't think the performance requirements go far enough in describing the performance of the work. I think the functional statements and the objectives should be grouped together at the same hierarchical level.

Specifically, going to the 'Deemed to Satisfy' (DTS) requirements which are in relation to waterproofing AS3740 - 2010 (AS3740) and AS4654.2 - 2012 (AS4654.2), those standards are not current. They have not been kept up to date and there is no linkage between the standards and the complaints that are running through the Tribunal and the Courts.

An example of this, is in relation to balcony and planter box leaks. AS4654.2 does not address those issues that have been the subject of the complaints. To make the standards effective there needs to be a linkage between the two that make changes to ensure those items which are the subject of the complaints I see over and over, are being addressed. The NCAT could provide this data to the NCC and SAI Global so that reoccurring inadequacies are addressed.

As to AS3740, an issue arose in a complex of 103 over 55's units categorised as adaptable housing. AS3740 does not address the issue of control of mineralised salt in tile screeds in bathrooms and neither does AS3958.1- 2007. There is no guidance for a builder on how to control the movement of moisture through tile screeds. Whilst AS3740-2010 acknowledges that moisture may cause deterioration, it does not tell you how to comply with the performance requirements of FP 1.7 of the NCC. Consequently, the builder is not technically at fault because he has met the DTS provisions but he hasn't met the performance requirements of FP 1.7 under the BCA - so who is at fault?

Are these concerns being addressed in the upcoming changes to the NCC due to be released in May 2019?

No, AS 3740 & AS 4654.2 are not scheduled for revision in these upcoming changes.

I was involved in a recent 'Hackathon' conducted by Victor Dominello, discussing home owners warranty insurance premiums whilst addressing the increase in building failures. One of the questions asked was, 'Why is there so many complaints in waterproofing?'

Giving you some statistics, in 2018, there was $43 million paid out by the State government in 809 claims and over 527 projects. There are 19,000 builders eligible for HBC insurance and 34% of builders are not obtaining cover (under $25K) and 15% of new buildings do not have building insurance (most likely because construction is over 3 storeys). 2012 was the worst year for losses.

The outcome of the hackathon was that the Government were going to look at increasing premiums for high risk builders and focus on geographical areas. I stood up and said the underlying issues were education , the quality of the Australian Standards and the fact that the standards are not up to date, contain incorrect product selection, poor installation practices and deficient inspection and certification methods. These issues did not feature as causal issues.

The Government is not going to source of the problem and in my opinion, the hackathon was a waste of time. The result will be an increase in premiums and will not 'fix' one future claim.

Do you have any other concerns with respect to the increase in waterproofing defects?

The increase in health issues arising from mould. In my opinion, this is fast becoming the next asbestos dilemma. Too many people are living in dwellings affected by waterproofing issues with high levels of mould present. There is no way this can be good for you and there are already many related health issues.

What needs to be done to fix industry?

You need to look at a six year cycle.

What needs to happen immediately are updates to AS3740 and AS465.2. These standards need to be brought up to date to reflect proper and workmanlike manner, not minimum standards. The standards do not presently provide for a 'system', if they are going to be a DTS system solution, they need to adopt a system that the builder is confident the DTS is going to work.

There should be a different system for waterproofing a bathroom in a timber framed bathroom compared to low movement construction, ie concrete slab and brick walls. But, if you go to AS 3740 there is no delineation between building structure types. Further, regarding manufacturing, there is no delineation between which materials you should be using for which job. If you are going to have a DTS system, you need to have solutions in there that builders, architects and designers can rely upon, so they can have confidence that the system is tried and proven and will work.

To succeed, you need to get standardised systems in place and what would flow from that would be checklists for certifiers so they know what they are to look for when they go out to inspect. If the building industry adopted a systems approach in the waterproofing which was incorporated in the Australian Standards, builders would then have a baseline for what is going to work, through education (i.e. TAFE courses) project managers will know the systems, waterproofers will install adequate systems because they will know what they have to do to make it work, and certifiers will know what they have to look for.

In two to three years, the standards could be updated to include a systems approach which incorporates checklists.

Three years after implementing a systems approach into the Australian Standards you would start to see a reduction in claims. Waterproofing defects don't normally manifest until year three but, you would find a change in the industry after year three and after year six, you would see a sharp decline in waterproofing defects.

Can you suggest any other ways to improve the system?

Another thing that needs to be implemented is a membrane register. Australia seems to be the dumping ground for waterproofing membranes that are not fit for purpose. Under section 18B(1)(b) of the HBA, it is an implied warranty that 'all materials suppliedwill be good and suitable for the purpose for which they are used'. Many materials, including membranes, have not been tested by CSIRO or Branz. They say a product complies but, when push comes to shove, they don't comply. A certifier asks for confirmation that materials have been tested and they haven't been tested, the developer is then left in the lurch.

A membrane register should be maintained by the Office of Fair Trading. If a membrane continually results in claims it should be taken off the register. This would result in the manufacturers ensuring their products are fit for purpose and are only being used in areas where they are capable of performing. It would also mean that manufacturers would take more care in selecting who they sell product too and how it is used.

Further, there needs to be the creation of standardised data sheets, so architects and designers can go to a manufacturer with information that is laid out in the same format. Some manufacturers spin data or don't give you the necessary information, if there were standardised data sheets for different membranes, everyone would be working to the same information and this would provide clear information for designers of systems, to make sure that the materials are used appropriately.

Putting it simply, if you use the right product for the right project, this won't cost any more and will save rectification costs. If there was a systems approach which works, this would solve all of these issues.

The cost of purchasing all of the referenced standards in the BCA is approximately $3000 to $4000. Then, in a month's time, there will be another update that immediately means the current standard is out of date. All of the standards, and updates should be made available to builders electronically as a part of their annual builders' licence fee. You would then get builders building better. If builders have access to all of the referenced standards in the BCA, then there is no excuse.

In summary?

You need to introduce systems to make it work. If there are approved systems for all critical wet areas, an architect can then have confidence that the design of the system has been properly considered, a builder can have comfort that if they use any one of the systems, that system will work and the certifiers will know what to expect and what to inspect. TAFE can then train waterproofers and all other associated trades to understand the systems and their requirements.

How creative can you be in your area of expertise with rectification scopes? Is it possible to come up with a unique solution that will solve the problem, reduce potential rectification costs for a builder and achieve the results the consumer is looking for?

In my experience with waterproofing failures and writing scopes of work for repair, you either fix it or you don't. There is no in between with water issues. Water always runs down hill and will always come back unless you fix it properly. There may be different ways that you can go about it and different materials you can use. But, you need to have a membrane that is on a stable substrate that forms a barrier to water coming into a building with flashings that direct the water out of the building.

Out of interest, what is the worst or most unusual defect you have seen in your time reporting as an expert on building defects?

I would have to say a job in Canberra where ?'ultra floor' was used. The construction was a high movement substrate and the membrane that was applied, was an acrylic based coating system which was applied in winter. What could possibly go wrong?

Acrylic membrane products, when laid, require 24 degrees Celsius and 55% relative humidity to cure. This is not going to happen in Canberra in the middle of winter. The system they used involved concrete footings and steel columns with concrete planks laid and then fibre cement sheeting laid over the top. It was like a micano set and leaked like a siv leading to a corrosion of the steel columns. It was a disaster.

For further information please contact:

Partner, Helen Kowal
Phone: +61 2 9777 8321

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

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