By SIMON COLLINS
The Government plans to spend $3.1 million over six years to find out what happens to water when it gets inside leaky buildings.
The Building Research Association, which will undertake the research, says it will break new ground internationally.
The association's manager of building industry research, Dr John Duncan, says the work will start with models developed in Germany and the United States that show how much water gets through various materials in given conditions of heat and humidity.
"They have a model which takes the material, looks at the properties and says, 'This is the diffusion rate through the wall'," he said.
"But what happens to the water then? Their model stops there.
"We want to know where the water goes once it has permeated through."
In many recent New Zealand apartment buildings, insulation has been packed in right up to the edge of external walls, so that any moisture that gets through seeps directly into the insulating material.
Last year's Hunn Report on leaky buildings said builders should install "a second line of defence - a means of getting the water away and a means of drying out any wet elements".
It cited a Canadian guide for timber buildings that recommends a 1-2cm air gap, or "cavity", between the external wall and the insulation.
But Dr Duncan said a cavity alone was not a "magic bullet" that would solve the moisture problem.
The new research would show the effect of moisture in various materials, and might lead to recommendations for better building methods, such as air cavities, he said.
"We do believe this modelling should have been done years ago by someone.
"The fact that no one in the world has done it indicates what a challenge it might be."
But the research was long-term, he said, and until then the association would keep running seminars and producing leaflets to tell builders what was already known.
Other research into building being funded by the Foundation for Research, Science and Technology includes:
* Industrial Research: $6 million to develop a new kind of cement based on alumina silicates instead of the present calcium silicates, using industrial wastes, natural clays and pumice, and eliminating carbon dioxide emissions.
* Canterbury University: $3.1 million to develop an earthquake-resistant building system using high-performance concrete materials.
* Opus Research: $3 million to develop roads that use cheap chip-seal methods but have the strength and quietness of asphalt.
* Institute of Geological and Nuclear Sciences: $2.2 million to isolate buildings from earthquake shakes in ways that are economic for houses as well as tall buildings.
Herald Feature: Building standards
Related links
Government pours $3.1m into leaky building research
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