Where the rot really set in

By ANDREW LAXON

Every time the Government blames "shoddy builders" for the leaky building crisis, Don Parkes sees red.

The Rotorua master builder, who has built more than 60 homes, is adamant he and other experienced builders are not responsible for the crisis.

He says higher authorities, who set the rules, or did not enforce them, are the ones to blame.

The official report into the crisis, by former State Services Commissioner Don Hunn, identifies poor workmanship as a problem.

It also points the finger at greedy developers, impractical architects and negligent building inspectors.

But the missing piece of the jigsaw is Hunn's separate report - expected at the end of the month - into the role of those higher authorities blamed by Parkes.

They include the industry's research arm Branz (Building Research Association of New Zealand), local councils and the Government-appointed Building Industry Authority, which oversees the industry and the building code.

Many builders say the leaky building problem goes back to the introduction of a new building code in 1991.

Instead of telling architects and builders how to design and construct houses, it concentrated on results.

Buildings had to be sturdy and leakproof, and the code often advised how to do this through "acceptable solutions" - approved ways of building which were recommended but not compulsory.

The Hunn report says it would be unfair to blame the code for the leaky building crisis.

But it highlights problems that occur when a performance-based code does not keep pace with rapidly changing building technology.

In the 1990s, New Zealanders moved away from traditional weatherboard and brick houses. Instead, builders began using flat, lightweight panels with a plaster finish, to give a more Mediterranean look.

These "monolithic claddings" accounted for less than 10 per cent of houses in the 1970s and 1980s.

But in the past 12 years, about 40 per cent of homes - including 80 per cent of the booming apartment market - have been built in this style.

The building code did not spell out how these new products should be installed to ensure they did not leak.

One solution, widely criticised within the industry as too permissive, allowed sealants on claddings, as long as they were not directly exposed to sunlight or weather.

The Hunn team's interim report in July blamed the replacement of mainly metal flashings with cheaper sealants as one of the prime causes of leaks.

The rapid growth of monolithic cladding in the 1990s had rung alarm bells before.

In October 1994, Greg O'Sullivan, a director of building surveying firm Prendos, warned in the Herald of "a potential time bomb" involving leaks and rot in new stucco houses.

He was supported a few days later by Auckland Master Builders Association president John Green, who believed the rush of complaints about cracking plaster and substandard work would turn out to be the tip of the iceberg.

At this stage, timber frames were still chemically treated with boron to protect them from insects. The treatment was also effective against rot.

But in 1995 the Government and the BIA approved regulation changes allowing the use of untreated, kiln dried timber. The effect on house building was dramatic.

Within a few years, the market was flooded with the cheaper new timber and boron-treated timber became hard to get.

Since about 1998 most new houses have been built with untreated timber, which rots far more quickly than the treated variety when it gets wet.

So why were the rules changed? Former Timber Industry Federation chairman and Forest Research Institute scientist Dr John Kinnonmonth, who chaired the committee which rewrote the standard, says it did not consider the growth of monolithic cladding and the leak problems emerging in Auckland.

The move was seen as radical, but everyone saw boron purely as an insecticide, he explains.

No one was thinking of its rot-resistant qualities, and industry thinking was that timber framing did not need protection from decay as it should not get wet.

Some committee members were not convinced. Forest Research's representative, John Turner, says he and Eric Moseley of the Building Officials Institute asked for their dissent to be noted in the minutes.

Kinnonmonth told the Herald that he had expected kiln dried timber to enter the market gradually and be used carefully by builders.

He was amazed - and later horrified - to see it take over so fast and be incorrectly used in places such as balconies, which were exposed to the weather.

Untreated timber was popular for several reasons.

Boron-treated timber arrived wet on the building site and took precious time to dry out.

Many builders complained that it moved as it dried, leading to "peaking" and "popping" in interior walls.

Timber giant Carter Holt Harvey, which led the campaign for change, was also under pressure to get rid of toxic chemicals at treatment sites.

Carter Holt, which was represented on the committee by its timber engineer, Pat Simperingham, strongly promoted kiln-dried timber as the "chemical free" way of the future through its Laserframe brand.

Industry sources say Carter Holt's drive to clean up its processing sites was a genuine factor behind the change.

Yet Forest Research scientists and timber decay experts Mick Hedley and Robin Wakeling say boron is one of the most harmless chemicals around - about as toxic as salt.

Even Green co-leader Jeanette Fitzsimons said in Parliament last week that the real problem chemicals for environmentalists were the copper, chrome and arsenic used in tanalised timber. The Greens had never opposed the use of boron.

In the end, untreated timber swept the market for a simple reason - cost. Industry sources say rival suppliers had their doubts, but could not afford to hold out against Carter Holt's cheaper product.

Most builders had to follow suit or lose work because treated timber added up to $4000 to their quotes.

Was the change to untreated timber foolhardy? Several industry sources say it was, although even the most critical admit no one then was predicting the disaster to come.

Building Industry Authority chief executive Bill Porteous says hindsight has made everyone wiser to the dangers of untreated timber.

He notes that when the authority confirmed the change two years later, it received only two public submissions and neither warned of the dangers of rot.

But at the same time, Porteous and the authority did start to receive specific warnings - mostly from Prendos consultant Phil O'Sullivan, who bombarded the BIA and Branz with letters and emails warning of the danger.

About 40,000 at risk homes have probably been built using the same methods since his first warning.

In April 1998, O'Sullivan wrote to the authority, describing the problems he was finding with leaks and rot in new buildings and suggesting a coordinated response. He did not get one.

By December - three letters later - he was worried enough to send a six page report on "Dry Rot in Monolithic Clad New Zealand Buildings".

In it he wrote; "I have little doubt that we are being confronted with a large proportion of modern buildings that leak".

His list of causes is virtually identical to the factors identified in the Hunn report four years later.

It includes the trend to monolithic claddings, reduced use of roof eaves, more complex and "artistic" rather than technically sound architecture, increased exposure to weather for the sake of views, greedy developers and too much subcontracting.

O'Sullivan says he received no response at all to this letter, which amazed him. He could understand the BIA not taking his word for it, but not the reluctance of officialdom to do its own investigation.

In 1999 the warnings to the BIA grew to a crescendo.

Phil O'Sullivan's brother Greg, Prendos' founding director, added his voice in October to warn of a "Cave Creek" disaster involving rotting decks and balconies.

Meanwhile Phil O'Sullivan sent more graphic pictures, including one showing a dangerously rotting balcony. More than 2 1/2 years later the Hunn inquiry team was shocked when O'Sullivan and others showed it exactly the same kind of danger.

The authority was then forced to issue a national safety warning over rotting balconies.

Yet it had known about the problem since November 1999.

Phil O'Sullivan also tried unsuccessfully to persuade the BIA and others to write much tighter rules on the installation of claddings - the crucial issue later identified in the Hunn report.

The issue bounced back and forth in emails for months with no real progress.

"I think you are putting the cart before the horse a bit here," BIA technical adviser Claire Benge told O'Sullivan after four months of discussion.

"I am just trying to get the cart and horse out of the stable," he retorted.

By this stage, O'Sullivan was gaining support from other influential voices.

John Kinnonmonth was so appalled by the consequences of his committee's decision to move to untreated timber that he wrote a report calling for a rethink.

"Increasing reports of water leakage and decay in modern houses lead one to conclude that insufficient attention was paid at the time of the 1995 review to changes in building practice that could increase the risk of decay," he wrote in September 1999.

It was not enough to blame bad building practices, Kinnonmonth concluded. The decision to allow untreated timber should be reviewed.

At Forest Research, Mick Hedley - stunned by O'Sullivan's reports of widespread rot - began testing to find out whether boron-treated timber did protect against rot.

In February 2000, his results confirmed what many builders and home owners had known for years.

Dry rot made big inroads on untreated timber, but boron-treated wood remained unaffected.

The research contradicted a high profile timber industry advertising campaign, led this time by Fletcher Challenge Forests.

Hedley has since done further research confirming his original findings. His latest tests - ordered by Branz this year when the scale of the leaky building crisis became obvious - show similar results.

By the end of 2000, Phil O'Sullivan was giving up on the Building Industry Authority.

In an eight-page report in November he again outlined the problem, noting that even a well-built modern house with monolithic claddings - his own, which he had tested - was leaking.

He did not have rot, as the house was built with treated timber.

"My experience is that most buildings suffer from external leaks and that a significant proportion has leakage problems that are severe," he warned.

"A catastrophic collapse of balcony is now a distinct possibility."

O'Sullivan said such building methods did not meet the building code's requirements that a building must be leakproof, made of durable materials and structurally sound.

He recommended a gap between the cladding and framing, enabling water to drain away, and a return to treated timber.

Both options are now being seriously examined, partly because of the urging of the Hunn report.

But at the time, his suggestions were virtually given crank status.

The BIA's Claire Benge described the cavity idea as "an unjustifiable increase in cost to the industry" and "an option the consumer can make by choice".

It would be wrong, she told O'Sullivan, to interfere with market forces by going beyond the minimum requirements of the building code.

Benge dismissed the re-introduction of treated timber - now recommended by a BIA working group - as "a backward step".

She added that she had only discussed the paper with colleagues.

It had not been formally presented to the authority.


Warnings and revelations:



1991: New building code says homes must not leak but does not set out rules for popular new monolithic claddings.

1994: Prendos and others warn of "potential time bomb" in leaking and rotting new stucco homes.

1995: Regulations change to allow untreated timber with no resistance to rot. The cheaper product takes over after vigorous timber industry promotion.

April 1998: Philip O'Sullivan begins warning Building Industry Authority of widespread rot and leaks. He calls unsuccessfully for an action plan.

September 1999: Dr John Kinnonmonth, chairman of the committee which approved untreated timber, calls for the decision to be reviewed.

October 1999: Greg O'Sullivan warns BIA of "Cave Creek" disaster over rotting decks and balconies.

November 1999: Philip O'Sullivan sends the BIA graphic pictures of a rotting balcony.

May 2000: Forest Research scientist Mick Hedley publishes research showing boric treated timber resists rot but untreated timber does not - contrary to industry advertising.

November 2000: Philip O'Sullivan again warns of a widespread, significant problem in modern buildings and urges the use of treated timber or wall cavities to drain leaks. Again his advice is not accepted.

June 2001: The Herald reveals huge industry concern over the problem.

March 2002: An independent inquiry begins, chaired by former State Services Commissioner Don Hunn.

May 2002: The inquiry warns in its interim report of a potential "major systemic breakdown across the industry".

July 2002: The BIA admits it is considering a return to treated timber.

August 2002: Based on the inquiry team's strong recommendation, the BIA issues a public safety warning over rotting balconies.

September 2002: The Hunn report finds clear evidence of a significant and growing problem. It predicts a $240 million repair bill.


* If you have information about leaking buildings,
email the Herald or fax (09) 373-6421.

Further reading
Feature: Leaky buildings

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