Leak solution draws flak

By SIMON COLLINS

New Zealand's seven-year experiment with untreated timber is ending in a clash of conflicting claims.

Auckland property consultant Philip O'Sullivan, who has campaigned against moisture problems in houses since 1998, said yesterday's decisions by the Building Industry Authority to require treated timber and air gaps in external walls were "ideal".

"It's been a long fight, but I think it's gone further than I hoped for," he said. "I'm very happy."

But Forest Industries Council chief executive Stephen Jacobi said the complete ban on untreated timber framing went too far and risked throwing hundreds of South Island forestry workers out of jobs.

The decision will be a blow especially to US-owned Weyerhaeuser and other producers of Douglas fir, which cannot be chemically treated and will therefore be banned from timber framing.

Chemical treatment and other changes announced yesterday will add between $4000 and $5000, or about 2.5 per cent, to the cost of the average new house.

Massey University property professor Bob Hargreaves said the changes also had the potential to devalue many of the 163,559 homes built during the seven years when untreated timber was allowed up to the end of last March.

Mr O'Sullivan said "probably 90 per cent" of the homes built in that period used timber that was either untreated or treated only for borer and not for mould.

The trend has already swung back to treated timber since the leaky homes crisis became apparent in the past year.

Yesterday's decisions are still not final. The authority has issued drafts of new "acceptable solutions" under the building code, but is accepting submissions on them until August 8.

The authority said it considered allowing untreated timber for internal wall framing, which should be less affected by leaks.

But in the end it decided to require chemical treatment in all framing timber because of the experience of leaks in the past seven years plus the dangers of "plumbing or roof leaks and problems associated with timber becoming wet during transportation, storage or construction".

"In addition, the authority believes that the proposed changes outlined in this document, specifying one treatment type for all framing, provide a simple regime that minimises confusion."

It proposes a colour-coded system with timber being dyed pink, blue or green to show the kind of treatment it has had.

On the other hand, it has conceded that a 2cm air gap will not be required for "low-risk" houses that are single-storeyed, with a roof slope of at least 10 degrees, eaves overhanging the walls by at least 45cm and in low wind zones.

The air gap will be required for all other houses. Mr O'Sullivan estimated that only 10 to 20 per cent of new buildings would fit all the "low-risk" criteria.

The proposed rules also include roof slopes of 3 to 10 degrees depending on roofing material, tighter waterproofing around windows, and rules to keep wall claddings and internal floors well above the outside ground level.

Carter Holt Harvey, the timber company that pushed for approval of untreated kiln-dried timber a decade ago, attacked the blanket return to timber treatment as "simplistic".

"Homeowners should understand that this proposal has the potential to affect the perceived value of every dwelling built since 1991, or some 230,000 homes nationwide, when the very concerning issue of weathertightness affects less than 1 per cent of these homes," said Carters chief operating officer Devon McLean.

The Government's Weathertight Homes Resolution Service has received applications for assessments of 1708 alleged leaky homes so far.

A Fletcher Challenge Forests executive who chairs the Building Industry Federation, Tom Nickels, said leaks in 1 per cent of new houses should not be allowed to push up prices for the other 99 per cent.

"This is not a crisis for the whole building industry," he said.

A director of Auckland valuer Sheldons, Gary Brunsdon, said there was no sign yet that buyers were shunning homes built in the period when untreated timber was allowed.

"The market is so strong that buyers who are a little more discerning and picky are often finding that they just miss out."

Mike Havill, of Waikato valuers Attewell Gerbich Havill, said the Hamilton market was also so buoyant that there was no noticeable effect yet.

But Professor Hargreaves said Canadian experience suggested that there would be an effect on the value of homes built in the period of untreated timber when demand for housing dropped.

"What buyers will be looking at is design features in houses such as no eaves, Mediterranean style, that were being built in that era. Those are the ones that people will have to investigate quite carefully."

He said it would take a while for this effect to show up because people would not try to sell leaky houses until the damage was repaired.