ToolBase Services
Skip to Main Content  
Advanced Search  
The Home Building Industry's Technical Information Resource

Back to Standard View
Building SystemsHome Building TopicsDesign & Construction GuidesBest PracticesConstruction Methods
Adobe Acrobat Reader required for PDF documents

PDF documents require the free Adobe Reader.

All PDF documents open in a new browser window. Close the browser window to return to the site.

Can you tell me about the new treated lumber for outdoor structural use and ground contact?

Question:

Can you tell me about the new treated lumber for outdoor structural use and ground contact?

Answer:

Generally, three methods of preservative treatment for lumber have replaced what we knew as chromated copper arsenate (CCA). These are Ammoniacal Copper Quat (ACQ), Copper Azole (CBA), and Borate Oxide (SBX) solutions that contain either copper or borates. The lumber costs are approximately 20 percent more than CCA, but the trade-off is low- or non-toxicity. Boards are purchased, handled, cut, and erected using conventional methods, however, fastener requirements for these boards with new treatments are different. All fasteners, hangers, and hardware that will come in contact with treated lumber in an outdoor (wet) environment must be G185 galvanic coated or stainless steel, but the two alloys should not be used together. For additional information see the PATH technology, Wood Preservative - Low Toxicity and the "Corrosion of Metal Connections in Preservative-Treated Wood Structures".