Engineered Wood Journal: It's the Moisture, Stupid

An important but perhaps little-noted conference on durability and disaster mitigation in wood frame housing was held last November in Madison, Wisconsin.

Why important? Because it underlined a nascent and potentially serious threat to the standing of engineered wood products among regulatory organizations and in the public consciousness. The issue is moisture in wood frame housing-how to prevent it, how to mitigate it. And, as some might have it, whether some building products-"composite" wood products in particular-are somehow complicit in building envelope performance problems that have been reported with what seems increasing frequency in recent years.

The conference was sponsored by the PATH Consortium for Wood-Frame Housing in cooperation with the Forest Products Society. PATH (Partnership for Advancing Technology in Housing) is a private/public sector initiative that seeks to encourage the development of new residential construction technologies. Its primary interests are energy efficiency, environmental sustainability, maintenance and operation costs, strength, and durability.

Engineered wood products, measured by those collective criteria, remain clear winners among the growing range of competing building materials. Unlike steel, concrete or plastic, however, wood will decay. That, of course, has been universally known since at least neolithic times. In fact, wood product standards, excluding those related to treated wood, do not even address the matter because it is also universally recognized that wood is to be used in ways that protect it from the cardinal cause of decay-long-term exposure to moisture.

So what's the problem? It's that wood products, field evidence suggests, are being exposed with rising frequency to long-term moisture. One of the reasons, no doubt, is that houses today are designed and built with more corners, angles, hips, slopes, nooks, crannies, and other design features that place greater demands on proper detailing and workmanship to keep the weather and water out. Those demands are not always met. Compounding the problem is the growing shortage of skilled construction workers, as explained in the story "Help Wanted".

Modern energy codes may well be another contributing factor. By requiring or encouraging houses to be sealed tight, these codes have also unwittingly exacerbated interior condensation problems, as well as indoor air quality concerns, a related and emerging building performance issue.

As the PATH conference made clear, the overwhelming body of building science suggests the solution to the problem is preventing moisture intrusion in the first place, through proper building practices, not villifying or banning products. To put it bluntly, it's the moisture, stupid.

It would be shortsighted, however, to expect that competing product industries will not seek to advance or exploit the notion that wood doesn't measure up on the durability scale. We've seen plenty of examples of that already. Nor should we be asleep to the possibility that, influenced by alarmist media reports, segments of the regulatory community or home buying public might come to question the performance merits of engineered wood products.

This issue is high on APA's radar screen. It should be high on yours too.

Also See from Engineered Lumber Journal:

Endangered Species

Emissions Control

Help Wanted

Forest Certification Part II

Technology Management

Industry Watch

Dateline APA

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