Rick Kleiner from the Southern Forest Products Association joins Bob to discuss current specifications for pressure-treated lumber. Kleiner explains that the copper arsenate that was once used as a preservative for pressure-treated lumber has been replaced by safer alternatives like ACQ or copper azol. Codes recommend that structural members be made of pressure-treated lumber, especially Southern yellow pine. Kleiner explains the tags on the lumber that indicate their recommended use. Lumber marked for below-ground use is treated with a higher dose of preservative than those rated for above-ground use. Pressure-treated deck members resist fungal growth, termites, and decay to maintain a strong and stable deck for as many as 40 years.

Bob meets with Wes Lohr, the general contractor for the River Hill homes, as his crew sets the sill and the first floor deck to frame the new house. Lohr shows Bob how the sill is constructed of pressure-treated lumber set on top of a sill sealer that protects the wood from wicking moisture in the concrete foundation. The pressure-treated lumber is drilled to receive the sill posts from the foundation, then bolted down to hold the decking tight to the base. The deck for the house is built of 2X10 kiln-dried lumber and 3/4-inch tongue-and-groove sheathing. The sheathing is first glued then nailed to the joists. Bob marvels at the speed of modern construction with a first floor deck and walls that can be completed in a day. Lohr estimates that the structure of the house and the roof will be complete in five or six days, with two more days of work to shingle the roof.

Bob goes to the Georgia Pacific pressure treated lumber plant in Sterling, GA to see how pressure treated lumber is made.