Who Do You Blame When Your House Leaks?
When you discover that your lovely nearly new house is leaking and rotting, who do you blame first? The builder of course. After all, they built the house, and your contract was with them, so that’s fair enough.
However, there is another important side to this story. Builders just assemble the parts of the house. They don’t design, manufacture or specify what they use. If what they are told to use is defective, then the result will be defective.
Builders were sold H1 and untreated framing timber that was not fit for purpose. Then by following plans approved by councils, based on NZ Standards and BRANZ Appraisals, they installed the timber in locations and with construction methods that were bound to fail. When they inevitably did fail, the builders were blamed because they were the easy targets.
However, the big timber processors were absolutely instrumental in the approval process and promotions that led to the inappropriate and widespread use of badly treated H1, or completely untreated UTKD timber.
When the leaky homes scandal erupted, the builders copped most of the blame and a lot of the costs. In fairness, there were shonky developers and builders out there. Untrained, unscrupulous, and the system allowed them to set up companies, build badly, then shut the company down to avoid liability. However, the majority of builders tried to do the right thing, doing the best they could with what they had.
What Did Builders Want?
Professional builders are part of the NZ Master Builders Federation, who in the past were represented on the Standards Committee helping to write our standards for timber treatment.
At the 1984 NZWPA (New Zealand Wood Processors Association) Meeting, the proceedings record the past President of Master Builders Federation Mr A. A. Curran as saying.
ADDRESS BY: Mr A. A. Curran
Immediate Past President, N.Z. Master Builders Federation Inc.
Mr Curran: Thank you for the invitation to be with you and to address you. It has been suggested that I talk to you on “what the builders want”, but I think it better that it be “what the builders need”. The builders want to be able to guarantee their product. The buck stops with the builder because he takes over, tenders for, and commits himself to the purchase of a product for which you have some responsibility. He enters into a contract to erect a building, or whatever, using your product. To a greater extent, indemnity schemes are going to be introduced, as we have, for instance, with the building performance guarantee, under which there is going to be a warranty for the structural performance of a building for a specific period of years. So we want a product we can have confidence in and stand by. When we specify our needs we want to be sure we are specifying the correct material for the particular use because performance is essential. So we look to you and your colleagues in the timber industry to advise us as simply and clearly as possible, the range of products, the range of treatments, properly marked so we can use them without any misunderstanding. This raises the question of cost about which everyone is conscious today.....it does not help to over-specify. We, therefore, need the product with the specification to meet the needs of the particular job.......In the event of failure, the property owner will not blame this Association or the timber treater of the timber merchant or sawmiller, - he will blame the builder. So what we ask for is a good product, properly branded, that will give adequate performance......In promoting your product it is essential that they can interpret it, understand it and use it correctly......We recognise that the industry as a whole, not just builders, but architects, engineers, millers, merchants, treaters......without a comprehensive knowledge of the whole range .......I ask you to help us by clearly and simply giving us the range of your products and the uses to which they can be applied. Thank you.
Quite clearly, the Master Builders Federation are asking the NZWPA to make correctly treated products, to label them clearly and to inform them clearly where each product should be used.
At That Time…
At that time, the Master Builders Federation had been on the previous Standards Committee which wrote NZS 3602:1975 specifying the timber treatment for homes. NZWPA members made framing timber treated to the C8 Classification as follows:
Timber treated to C8 required adequate ventilation and protection by external walls. Adequate ventilation is described in carpentry books of this era as brick veneer, sarking (spaced), cavity battens, or spacers to separate sheet claddings from boron treated framing.
An interesting but important point is the requirement that C8 timber needed to be “protected by external walls and adequately ventilated”. A wall is comprised of the framing and the external lining. So, if C8 timber had to be protected by an external wall, it couldn’t be part of that external wall. In other words, this specification, as written couldn’t be used for external walls. But there was no specification written for timber that was part of an external wall. A small error or oversight which was carried through to later revisions of the standard with serious consequences.
However, C8 treated timber with boron at 0.8% BAE, in a ventilated wall, is very durable so in practice, this proved to be fit for purpose. Even when used behind in stucco walls without good ventilation, it was still able to last for over ten years, so no claims eventuated.
The mid-1980’s – Bad Advice from BRANZ and Change to Australian Standards
1985 BRANZ Appraisal 118 appraised Insulclad (EIFS Polystyrene/Plaster cladding) as a face fixed cladding without window flashings. Framing behind this cladding had no ventilation, which conflicted with NZS 3602:1975. BRANZ were paid for many more Appraisals for face-fixed claddings up until 2004. No face fixed cladding Appraisals remain valid.
Even with no ventilation or effective flashings, the well-treated C8 framing protected timber and kept claims at bay.
It is noteworthy that BRANZ researcher Cunningham in his 1983 report rp31-1 stated that ‘must never enclose framing’. This was presented to the 1983 World Durability Conference in London a couple of years before. Somehow BRANZ didn’t follow their own research.
1988 NZ Standards in MP 3640:1988 adopts Australian Hazard Classes:
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C8 was split into H1- insect hazard and H2 - low decay hazard and termites.
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H1 framing had no boron loading charge but keeps 0.1% BAE core retention (our testing shows treaters kept using the old C8 loading charge through this period but changed the branding to H1). H1 also must be protected by external walls and be adequately ventilated.
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H2, although mentioned has been removed from the Standard. Not for sale in NZ, awaiting approval of using boron in H2 timber exported to Australia.
The Master Builders Federation were no longer on the Standards Committee for this or future revisions.
In relation to Mr Curran’s request for suitably treated and labelled timber, H1 at 1988 was in practice still treated at the same loading as C8 so this was merely a branding change. Mr Curran’s builders could safely just substitute C8 with H1 Boron and everything would still be OK.
The 1990’s Treatment Drops, But Were Builders Told?
In the 1992 NZ Standard MP 3640:1992, the approved treatments for H1 changed markedly to allow kiln-dried boron at 0.04% BAE and 0.1%BAE cross-section retention (1/8th of the retention of C8). Permethrin insecticide which gave no protection whatsoever against decay was approved. Wet frame boron continued with 0.1%BAE core retention.
Shows reduction in boron for softwoods to 0.04%BAE core and 0.01% Cross Section, Permethrin (flyspray) now approved
By now framing timber was coming from the faster-growing immature plantations and the soft sapwood really had to be kiln-dried to stabilise it. Treaters moved to the ‘dry frame retentions’ which were 1/8th the boron strength of C8. Manufacturers such as James Hardie were specifying kiln-dried framing behind their Harditex cladding. At worst, the new H1 decayed just as quickly as untreated timber, at best, it would last for one or two wettings before giving up.
I can find no media releases or articles advising builders that H1 had changed from well-treated decay-resistant C8 timber to just a trace of boron or the equivalent of fly spray.
Carters Lobbying for Untreated Timber Succeeds
In 1995, another nail in the coffin for timber treatment was hammered home when NZS 3602 1995 was released. Carters, one of the largest timber suppliers, lobbied for the wider use of untreated timber. They produced a five-volume submission to the Standards Committee, supporting the use of untreated timber for dry interior conditions. This appears to have been instrumental in having UTKD timber listed in Table D of the revised Standard.
To further bolster their marketing, Carters then paid BRANZ to update BRANZ Appraisal No. 279 to now include the use of UTKD timber for framing, virtually without limitation. No testing for decay resistance and minimal research about what would actually happen to the timber in service seemed to take place.
In any case, history is the best proof of process and the massive decay problems and subsequent withdrawal from the use of UTKD in framing is incontrovertible proof that it was not fit for purpose on external walls and should never have been sold for that use.
Carters Mislead With Untreated Timber Advertising
Once Carters had UTKD in the standards and a wide-open BRANZ Appraisal for its use in framing, they promoted heavily in the marketplace, attracting criticism from industry leaders including John Kininmoth, the Chair of the Timber Preservation Council and a member of the Standards Committee. He wrote a strong letter to fellow committee members seeking a review of NZS 3602, but to no avail.
In 2002 Carters were found guilty by the Advertising Standards Complaints Board of misleading advertising by claiming that kiln-dried chemical-free timber performed similarly to H1 treated pine timber.
One of Carters claims, which Advertising Standards found to be in breach of the Act was:
"Q. Is my builder using the best materials when he uses chemical-free Laserframe?
A. Yes. There is no better framing than Laserframe. It’s environmentally friendly. It has the colours to show it has passed the strength test. It is high-temperature kiln dried, so it will be straighter and more stable."
Here is an example of the propaganda written by Carters to mislead the public by quoting ‘experts’, including their own Development Manager and BRANZ General Manager – the same independent BRANZ whom Carters had paid to Appraise their product.
Carters essentially claimed that H1 boron treated timber never controlled decay or termites and was no more decay-resistant than treatment-free timber. This is blatantly untrue. The H1 boron made from 1988 to 1992 was well treated and very decay-resistant. Even the later H1 treated with the ‘wet frame boron’ process provided a reasonable level of protection for small leaks.
Interestingly, Carters go on to admit that their H1 at best provides very temporary protection against fungus, then in the next paragraph recommend using it in subfloor applications because H1 treatment provides greater protection where the higher moisture levels are expected. You can’t have it both ways Carters. They were partially correct in the first instance in that H1 does offer some protection against fungus, however, the potentially moist conditions in a subfloor space required a far higher level of treatment.
In the photo above we can see what happens to H1 timber in a moist subfloor space. The timber has been attacked by surface moulds and decay.
According to their ‘experts’, If any houses rotted, it wasn’t because the timber was untreated but because of bad building and weathertightness which led to leaks.
Other Timber Manufacturers Join the Bandwagon
To compete with Carters, other timber suppliers had to climb on the bandwagon and offer the same. Within a short time frame, UTKD became the norm and even the poorly treated H1 boron became harder to find.
Councils accepted that this and one council even refused to allow H1 saying it would be wet so not pass the pre-line inspection. The ease of manufacture of UTKD compared to CCA treated H3.2 made it difficult for builders to even source dry H3.2.
As far as the builders were concerned, everyone who was important was saying that UTKD was the product to use, that was what was being specified, it was promoted by BRANZ, supplied by the industry and accepted by the council, so that is what they used.
Builders Are Left to Take the Blame
So where does that leave Mr Curren’s open request to the New Zealand Wood Processors Association for treatment, clarity and information?
Were his builders told that the timber they were now using would decay unless every single detail was made 100% weatherproof, and stayed weatherproof for the life of the building?
Was it explained to them that to use UTKD for framing, they somehow needed to ensure that it would stay below 18% moisture content for the life of the building, otherwise it could rot?
And that maintaining that low level was going to be virtually impossible, especially behind absorbent direct fixed claddings, such as Harditex and stucco and windows that all failed BRANZ leak testing in 1986?
I bet that wasn’t clearly written on the Product Data Sheets and promotional literature.
When the leaky building scandal erupted, it was the builders who attracted the biggest share of the blame, and many were hit with big claims. However, it has always been known that buildings, even well-built ones, leak, or will leak at some stage. The house needs to have a safety factor to allow for this without being damaged. Historically, this safety factor was well-treated timber.
Maybe the builders should have known better, ignored NZ Standards, BRANZ Appraisals, Councils approvals, Timber Suppliers media, and Architects Specifications and substituted well-treated timber for UTKD? That would have made them uncompetitive and wide open to claims by straying from Standards.
The timber processors must accept a big share of the blame for the leaky homes scandal.
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They failed to inform their customers - the builders, about the falling timber treatment standards and the impacts.
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They played a big part as Standard Committee members presiding over the changes in the standards.
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They promoted the use of undertreated H1 and untreated UTKD timber in applications and locations where it was not fit for purpose.
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And, they failed to warn anyone, even when it became obvious that their products were not meeting the durability requirements of the Building Code.
However, they have been able to take their profits and walk away unscathed. It’s just a shame that the poor homeowners weren’t as fortunate.
Should Carters, Fletcher Timber and the others be in court alongside James Hardie? If they had never pushed their untreated timber, if they had put the consumer's interests above their commercial interests, the leaky building crisis couldn't have happened.
Tags:
Carters,
Untreated Timber,
Treatment Free Timber,
Master Builders Federation