Wood Preservatives See Major Gains Following AWPA Standard Revision

Wood Preservatives See Major Gains Following AWPA Standard Revision

Earlier this year, the American Wood Protection Association (AWPA) revised the language of one of its standards, and the change has brought on a dramatic shift in the practices of those who produce and sell treated wood, as well as a great deal of debate and, among some parties, even animosity over the proper response to AWPA’s standard revision.

What Does the Standard Say?

The standard in question involves treated wood building materials like the joists and beams of a deck’s framing, and it distinguishes between two Use Categories: one that defines the proper use of treated wood in situations where the wood comes into contact with the ground (UC4A) and one that applies where the wood is above the ground (UC3B). Ground contact means that wood is more exposed, and more vulnerable, to decay at the hands of threats like mold and insects, so wood that is treated for ground contact requires more preservative than wood treated for above-ground use.

The standard’s new language addresses some of the trickier situations somewhere in the middle: What about wood that isn’t touching the ground but might otherwise be at greater risk of decay? If it’s near the ground, for example, like a lot of joists and beams often are, dead leaves and other debris could build up on the wood’s surface. If it’s on the underside of a deck, there could be little air circulation and moisture could sit stagnant, encouraging mold. And in many cases, the wood in these kinds of situations is going to be difficult to access and therefore difficult to repair or replace. So perhaps these types of decking materials should be treated for ground contact even though they’re installed above the ground. The answer, according to the revised standard, is: maybe and maybe not.

What Does the Standard Mean?

Not all deck joists need to be treated at ground-contact retention rates; in many cases, the wood is far enough from the ground, well enough ventilated, or accessed easily enough that above-ground treatment will suffice. That’s what the revised AWPA Standard U1 says, anyway. The standard provides guidance as to how to specify the kind of wood that should be installed in some of the tricky situations above, but it leaves it up to contractors, inspectors, and local building codes to decide which is the appropriate Use Category. As The Journal of Light Construction emphasizes, the response to the revision could have taken any of a number of forms, some more substantial than others, but it didn’t have to be an all-out game-changer.

What Does this Mean for the Preservative Market?

The treated wood industry’s response to the standard revision has been far more dramatic than anybody probably expected. Especially striking is the heated (and sometimes hostile) debate that has taken place over the proper interpretation of the new standard language, including volleys of press releases back and forth among both preservative producers and wood treaters, and threats to appeal the revision.

But the most significant change has come at the hands of the retailers of treated wood, many of whom have responded to the standard revision by shifting their lumber stocks to contain more ground-contact-grade wood and less above-ground-grade wood. The Home Depot announced in mid-April that it had begun to convert its stock, and a ProSales survey shows that many others have followed suit, or plan to, as they make new orders.

With more ground-contact-grade wood in stock, and less treated for above-ground use, this move on the part of retailers will have a significant impact on the value of the wood preservative market going forward.  Preservative producers such as Koppers and Lonza, whose micronized copper azole products dominate in decking lumber, just received an early Christmas present.

Learn More

For more insight into the state of the wood preservative industry, see Wood Preservative Market in the US, a new Industry Study from the Freedonia Group. This comprehensive report provides the following:

  • Historical demand data and forecasts
  • Market environment factors
  • Industry structure
  • Company market share

About the Author:

Matt Breuer is an industry analyst at The Freedonia Group, where he writes industry studies focused on the US chemicals and chemical products markets.

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