Houses rot as industry quarrels

By KEVIN TAYLOR

The timber frames of a growing number of new houses are rotting, some only months after they are built, as the building industry squabbles over the use of untreated kiln-dried framing and cheap cladding.

No one knows how many of the 20,000 new dwellings built each year - including 7500 in the Auckland region - could be affected.

But the Building Research Association is so worried that it has set up a group to investigate.

In one case, a house frame was found to have rotted in seven months.

The distributors of the kiln-dried timber frames say they are a good product, and blame bad workmanship by builders and poor cladding which lets in moisture.

Timber Industry Federation executive director Wayne Coffey says: "They have to keep buildings watertight. It's a workmanship and cladding issue."

Others in the industry say the removal of expensive eaves on modern houses allows rain to leak into the frames.

The issue is to be debated at a conference of the Certified Builders Federation in Hamilton today.

Greg O'Sullivan, founding director of Auckland building inspection firm Prendos and president of the Institute of Building Surveyors, says that he and his brother, Philip, have been trying to alert the industry to the issue for three years.

He wants the untreated kiln-dried framing banned until cladding technology improves.

He also wants banned in high-risk structures such as balconies and cantilevered deck

Philip O'Sullivan, president of the Claddings Institute and a Prendos consultant, told the Weekend Herald that he was dealing with a house where the frame had rotted after 15 months.

A study of 300 pre-purchase building reports from Prendos showed 80 per cent of exterior claddings had some defect, and 60 per cent let in moisture.

The Building Research Association information services general manager, Russell Cooney, says the research is alarming.

And he admits that the association does not know the extent of the problem.

"We also don't know its geographic distribution," he said.

But most reports show the problem is surfacing most often in Auckland, the powerhouse of the country's building industry.

Mr Coffey of the Timber Industry Federation says untreated kiln-dried framing timber now dominates the market because it is easier, lighter, cheaper and quicker than other materials.

But Greg O'Sullivan says it is unrealistic to expect buildings to be completely watertight, and the problem is with the untreated framing.

"You can't keep a building dry. It's an impossibility."

Framing timber has traditionally been treated with boron, which also provided some rot resistance.

A change to the building standards in 1996 allowed untreated kiln-dried timber to be used.

The standards assumed buildings would not leak.

But the change came with the disappearance of the use of eaves from new houses, some shoddy construction, and the rise of so-called chillybin claddings such as stucco, fibre-cement and polystyrene.

Mr Cooney says that linings and claddings are very good at hiding the problem, and homeowners may not know what is happening behind their walls.

"It's a hidden problem and it's going to be an unfolding and emerging problem."

The organiser of today's conference in Hamilton, the Certified Builders Association, was reluctant to comment in case publicity deterred suppliers from taking part in an open forum on the issue.

But CBA chief executive Garry Shuttleworth said the industry had major concerns.

Consumers Institute chief executive David Russell says the institute has not received any complaints he knows of, but admitted to being sceptical about untreated kiln-dried pine.

"You have to be so careful in handling the stuff," he said.

"It's asking for a high degree of skill and knowledge on the part of the builder."

Mr Russell did not know how prevalent the problem was.

"It's one of those things that's all covered up.

It's only going to become apparent when the house starts falling apart."