Leak hunter gets cold shoulder

The Government's leaky building service has rejected a new business offering infra-red camera inspections to solve leaky building issues.

Dave MacDonald, director of DryBuild Holdings, said he began using a thermal imaging camera to detect weathertightness issues in July.

But the Government's Weathertight Homes Resolution Service will not use DryBuild because it was not a qualified nor certified inspection business, MacDonald said. Nor was it a Building Research Association-accredited adviser.

MacDonald said he held neither qualification and was formerly the owner of Cycletreads, a Christchurch motorcycle shop. But he is studying thermography and would be fully qualified in about two years.

Nigel Bickle, acting national manager of the service, said thermal imaging techniques had not been accepted as an industry practice.

"Nor has it been accredited for use in New Zealand," Bickle said. Image-based investigations had a limited role and the service's assessors used a range of testing methods and equipment including moisture meters, destructive testing, laboratory examinations, visual inspections, off-site investigations and photographs, Bickle said.

Despite rejection, MacDonald said he had great faith in his new business, which got United States federal and militarily clearance to import a thermal imaging camera for non-invasive house testing, which he says could save people thousands of dollars.

But Phil O'Sullivan of leaky building analysts Prendos said he doubted the equipment would be of much use to anyone.

"I tried it twice. The first time it was a complete, dismal failure and waste of time and the second time was only mildly better," O'Sullivan said. Camera inspections of internal house walls were hampered by features like parapets and balustrades, he said. The cameras rely on detecting large heat differences, often difficult in Auckland.

O'Sullivan, president of the Claddings Institute and an early whistle-blower in the leaky buildings saga, said infra-red technology would be of more use in places with a larger thermal climate variation, like Vancouver.

Prendos uses a five-step process in its investigations involving visual inspection, non-destructive testing using moisture meters, drilling holes and inserting probes, cutting holes in walls and inspecting structures and further inspection once claddings had been removed for repairs.

Prendos has 10 building inspectors specialising in identifying the source of leaky building problems and reporting on how to fix them, O'Sullivan said.

But MacDonald reckons his technique works better than commonly accepted investigation methods.

"Thermal imaging can provide the home owner with more information relating to a weathertight issue, such as sourcing the cause of the leak, the entry point of moisture.

"One property owner in particular had spent thousands of dollars over a three-year period trying to rectify weathertight issues. We came in with our camera and within a matter of hours had identified the moisture source: a small leak causing big problems, originating in one exterior light fitting," MacDonald said.

"This technology is new . . . We will continue to fight for official recognition on a product already approved in America, Europe and Asia."

Looking for leaks

The Government's Weathertight Homes Resolution Service demands assessors:

* Be specifically trained in the industry.

* Adhere to standards set by NZ Institute of Building Surveyors.

* Have current practicing certificates from a relevant professional body.

* Update knowledge in leaky building damage and remediation procedures.

Expert panel

Attempts to stamp out leaky building issues have given rise to a proposal for the formation of a new professional group.

The Claddings Institute wants to form a building envelope panel of experts on building exteriors.

Institute president Phil O'Sullivan said the panel of scientists, architects and engineers would focus on weathertightness design issues.

Institute executive officer Neville Scott said panel membership would depend on an applicant's ability to demonstrate significant and relevant experience in the design of the building envelope.

It would be a "collegial environment" for sharing and development of knowledge.