If your wood deck is older, it may begin to show signs of dry rot, even if it’s made of pressurized wood. Dry rot includes spongy and discolored wood that can flake off or disintegrate when it becomes wet. You can use a screwdriver to test areas of a wood deck for dry rot. When you see signs of dry rot, it’s important to address the problem and get it repaired as soon as possible, because the problem will only get worse and the deck may become dangerous to use.