How to Pick a PT Post

While it’s not a structural problem, pressure-treated posts sometimes get a little twisted after installation. That’s because PT lumber contains a lot of water from the treatment process that needs to dry out, and because the posts are typically cut from the center of a log — you’ll often see the pith at both ends. The wood cells in the first few growth rings are prone to distortion as they dry, especially when the growth rings are wide. To minimize twisting, select pieces that have the pith as close to the center as possible at both ends, which indicates that the grain is straight. If the post doesn’t come from the center of the log, look for pieces where the growth-ring orientation at the ends closely parallels one of the faces.