Tricks for Treated Lumber
It's been seven years since the Environmental Protection Agency announced the phase-out of chromated-copper-arsenate (CCA)treated lumber. CCA's replacements, although safer, bring different challenges to your outdoor projects. Here's what you need to know.
Lumber
Alkaline copper quaternary (ACQ) and copper azole (CA) accepted CCA's abdication of the outdoor-lumber throne with a fairly smooth transfer of power. Both treatments provide similar, high levels of preservative power with arsenic-free chemicals.
In order to achieve the preservative power of CCA, ACQ and CA ramp up the amount of copper used. But because copper speeds corrosion in ferrous metals, steel fasteners must be chosen with care. (See photos.)
The newest kid on the block, micronized copper quat (often marked MCQ) substitutes dissolved copper with a finely ground copper particulate. While it doesn't yet have the long, proven track record of ACQ and CA, proponents claim MCQ achieves the same level of wood preservation and rot-resistance with a lowered level of fastener corrosion.
Add your comment
Please confirm your comment by answering the question below and clicking "Submit Comment."














where do you find .60 treated deck material
1/4/2012 03:53:16 PM Report AbuseAlways check the number on the label stapled to the wood, .20 Won't last long. Most big box stores only carry .20. If you want your treated lumber to last any length of time get .40 or above. I only buy marine grade .60 when I buy treated lumber. Landscape timbers are all rated .20, so expect to replace them much sooner than you would think. Note that the .20 label says "not for ground contact," but these are "landscape" timbers so does that make sense?
6/15/2011 12:16:16 PM Report AbuseTo save this document without select and paste, print the document to a PDF Printer. Go to PrimoPDF.com and download the FREE printer software. When you print to the PRIMOPDF printer, it will create a PDF document of the article you are trying to print at a save location you choose. No more copy and paste.
8/6/2010 02:01:44 PM Report Abuse