Pressure switch - Editor's Note

Tools of the Trade, March-April, 2004 by Rick Schwolsky

Talk about switching chemicals used in pressure treated lumber from chromated copper arsenate (CCA) to other treatments is nothing new, so I wasn't surprised to learn about the recently adopted EPA-proposed changes that led to a transition away from CCA to new treated materials. But, like a lot of you, I was caught completely off guard by the jobsite implications the new lumber imposes on builders in terms of fastening the new materials.

The lumber industry has voluntarily adopted new EPA rules for phasing-out CCA-treated lumber for most residential use after Jan. 1, 2004. There are several alternative treated lumber products available to replace CCA; the most commonly mentioned alternative is a non-arsenic-based treatment called alkaline copper quaternary (ACQ).

But testing shows that ACQ is much more corrosive than CCA, posing a serious threat to the fasteners and hardware holding the material in place. People are worried that even 1/2-inch anchor bolts aren't safe in contact with ACQ-treated lumber. And I'm worried that the lumber industry, in trying to solve one problem, has created another, leaving cost, confusion, and corrosion in its wake.

As of this winter, wood producers were recommending a minimum of stainless steel fasteners or hot-dipped galvanized fasteners that meet ASTM A153 standards, and connectors that meet ASTM A653 Class G185 sheet or better. Many tool and fastener manufacturers, including Senco, Stanley-Bostitch, and Paslode, jumped into early action to test their fasteners so they can guide customers to products that withstand ACQ, and a few have introduced new products specifically for the new materials.

Another important player in this drama is Simpson Strong-Tie, which has conducted extensive tests on CCA, ACQ, and a promising sodium borate treatment called DOT. This last chemical is actually less corrosive than CCA, and more environmentally acceptable. Borate-treated lumber is already available; it's not suitable for outdoor use and soil contact, but may be the best option for framers to use for sills and plates because no change in fasteners and hardware is required.

Framers are freaked. One large framing contractor we know who has been tracking these events even caught himself on one project and had to go back and re-anchor ACQ sills with stainless steel because he didn't realize the lumber switch had already happened. Another had a revolt on his hands due to a last-minute switch-out of a delivery to ACQ, and his last-minute instructions to change nails.

If you're framing houses, find out if your lumber supplier can deliver borate-treated materials for sills and wall plates--right now it seems like the best bet. If you're building decks and other outdoor wooden structures, check with your fastener and connector manufacturers to get their recommendations for which products to use with the lumber you're using. There's hope among the companies most affected by this situation that things will smooth out quickly once everyone gets up to speed. I hope they're right. In the meantime, don't get caught unaware.

RICK SCHWOLSKY, EDITOR-IN-CHIEF RSCHWOLSKY@HANLEYWOOD.COM