Leaky buildings worry industry

New Zealand's construction industry is trying to come to terms with leaking new buildings, a nightmare that cost Vancouver's building industry more than $1 billion.

Next Monday and Tuesday, the industry in Auckland will gather to hear Canadian experts who have studied problems which led to leaks and rotting timber framing in about half the condominiums in Vancouver built from 1986.

But what Canadians called the "leaky condo crisis" is also hitting the construction industry here. Experts are investigating a large new Auckland development - Summerfield Villas - to find out how and why water is coming in.

The 93 units on the corner of Richmond Rd and Sackville St in Grey Lynn were finished only last year but problems are already emerging, particularly around the dormer windows and roof flashings.

Developer David Gaze and builder Mainzeal Construction are looking into the problems and are erecting scaffolding over the entire complex - three villas at a time - to get to the root of the problem.

Gaze said moisture meters and infrared cameras were being used to examine the building materials.

He said that although there were problems with "only one or two of the villas", he had decided to investigate, adding that he did not want negative publicity because he was doing the right thing by taking the initiative.

Gaze criticised the Building Research Association for not moving fast enough.

"It surprises me that BRANZ is not getting on to it and specifying alternative methods on the cladding applications to ensure the timber doesn't move."

Mainzeal Construction general manager Chris Hunter said one of the problems at Summerfield Villas was defects in the flashings where rivets had popped, allowing water to leak in, particularly around the parapets and dormer windows.

But the units in Grey Lynn are just one case where problems have arisen lately. The industry is facing difficulties over millions of dollars of work.

Construction litigation lawyers such as Kerry Knight of Knight Coldicutt in Auckland are handling claims against developers over new buildings leaking. He has formed an alliance with a Melbourne lawyer, Kim Lovegrove, to add expertise at his Princes Wharf office.

The Building Research Association has spearheaded an industry initiative, the Weathertight Buildings Project, aimed at working out the size of the problem and how to resolve it.

As part of this initiative, the Claddings Institute has organised an Auckland seminar on weathertightness next Monday and Tuesday, saying the problem with leaking buildings is one of the major issues facing the construction industry.

"Too many new buildings are leaking, due to inadequate design and construction," the institute says.

"The causes are simple but reliable solutions are elusive. New materials often present unexpected interactions."

The forum will hear about the problems the Canadian building industry faced.

Several Canadian experts will address the two-day meeting, including Michael Wilson of RDH Building Engineering and Don Hazleden of HouseWorks Building Science - both of Vancouver - and Michael Lacasse of the Institute for Research in Construction, National Research Council, Ottawa.

The meeting on Monday will be held at the Conference Centre, Wright Stephenson House at 585 Great South Rd in Penrose.

The convener will be Adrian Bennett, the Building Research Association weathertight buildings manager.

A commission of inquiry was held into Canada's leaking condominiums.

Canada's Wood Products Research Institute estimated that half of all multi-family units built after 1986 leaked, costing the Vancouver industry at least $1 billion.

The Canadian Wood Council found that Vancouver condominiums showed signs of decay in as little as three years, homeowners had to pay for repairs and buildings were being repaired twice for the same problem.

The problems in New Zealand are like those in Canada, with similar causes of leaks and subsequent rotting of timber framing.

The Weathertight Buildings Steering Group - which is trying to find out how many places leak here - published an article in the latest issue of the Building Research Association's Build magazine, which blamed various factors for the problems.

"The problems that we face in New Zealand - work being carried out for the lowest cost, low skill levels, incomplete drawings, missing or poor details - also affect the construction industry in North America," the article said.

"There, industry associations, Government agencies and manufacturers are working together to combat these problems by introducing training courses, quality procedures and educational publications.

"Similar measures will need to be developed and implemented in NZ as part of the overall approach to weathertightness."

The article had some good news for our industry: "Despite being several years behind the North Americans in recognising and reacting to the weathertightness problem, it should be easier to resolve weathertightness issues in New Zealand because our industry is compact, there are fewer variations in climate and construction types and we have a national building code.

"But because the New Zealand industry is so small on a world scale, funding for initiatives to improve weathertightness will always be a limiting factor."

John Sutherland, adjunct professor of architecture at Unitec, blames house design since the 1990s for much of the problem.

Mock-Italian houses built without eves or overhangs are more likely to have problems than older-style New Zealand houses.

Noel Casey, a Christchurch building consultant, gave a graphic example of how people's lives could be endangered by water leaking into buildings.

In Build, he showed a rotting untreated timber balcony balustrade on a 10-year-old South Island house, clad in texture-coated fibre-cement. The house was built on a hillside.

The first the homeowners knew of the problem was a small patch of fungal growth appearing in the cladding. Investigations showed the balcony was dangerously rotten, carrying a 40 per cent moisture reading. "It should be about a third of that," he said.

The lives of the homeowners or their guests were at risk.

Weathertight Buildings Project