The boards on my four-year-old deck are shedding splinters along grain lines. The decking is yellow pine that has gone through a heat-treating process, and the supplier’s warranty states a 30-year term. I’ve spoken with the supplier, who might replace the product, but I’m not interested in using the same wood. If I were to get new wood, such as cedar boards, and overlay the existing decking with the new boards, what problems, if any, could I expect?
David Rierson, via email, None
Senior editor Andy Engel replies: Moisture would get between the layers of decking and wouldn’t have much of an opportunity to dry. The bottom of the new deck boards would be wet all of the time. As a result, the bottom side of the boards would expand at a different rate than the top side, leading to cupping. You could also end up with a biology experiment growing between the layers. For those reasons, I recommend tearing up the existing material before putting down the new.