Guest commentary: On treated wood

Spring is here, which means deck season will soon be in full swing. From deck builders to do-it-yourselfers, customers are likely to start asking for advice on the best products to get the job done.  One topic that is likely to surface this year relates to changes in the American Wood Protection Association (AWPA) Use Category System for treated wood.

The AWPA is expected to publish adjustments to its Use Category System (UCS) standards for treated wood in May or June.

The updated language adds a footnote to the UC3B Above Ground and UC4A Ground Contact use categories that states: “Joists and beams shall be treated to requirements for UC4A when they are difficult to maintain, repair or replace and are critical to the performance and safety of the entire system/construction.”

Some may interpret this to mean that Ground Contact treated lumber should be used for all components of a deck. However, it is important to recognize that Above Ground treated lumber remains an acceptable option for most common decking applications.

As with any project, customers will look for guidance, and want to have access to the right materials for their job.  By understanding the best uses for each type of treated lumber, you will be equipped to help them get the job completed correctly.

Here is critical information you need to remember:

Above Ground treated wood remains code compliant for typical exterior applications like the structural framing of decks, which includes deck joists and support beams, decking surfaces, railing components and fence pickets.

Ground Contact treated wood should be used in applications where the wood is in direct contact with the ground—for example, when decks are built directly on the ground; deck and fence posts that are set in concrete; or in cases where leaf debris, soil or vegetation may build up or accumulate over an extended period of time. Treated material used for landscape walls should be treated for heavy duty Ground Contact use (UC4B).

The Bottom Line: Dealers and retailers looking to best serve their customers should continue to stock an assortment of product that includes both Above Ground and Ground Contact treated wood.

Most important, be sure your customers are using the right materials for the right application.  The value of Above Ground treated wood is that it generally uses fewer chemicals than the comparable Ground Contact product. 

Bill Fields is president of Viance, LLC. The company maintains a site with more information at treatedwood.com/options.