Wood rot is technically a fungus that breaks down wooden structures. Signs that wood rot has overtaken the wood in your crawl space include discoloration, shrunken size, cracks, and splintering in the wood. In some cases, you might also notice strips of white on rotting wood. This is a particular variant of wood rot known as dry rot. Wood rot is relatively easy to identify, especially because it makes the wood look so different from its original condition.