Most times people do not see or notice wood rot until it’s too late. Depending on where the wood rot is located, will determine the type of damage that can occur if left untreated. There are many reasons why wood rot happens, but one thing is that it can bring in moisture leading to mold issues. Other times the roof might need new roof decking. When sheathing is exposed to moisture frequently or little to no ventilation, there is always a chance it will decay or develop wood rot.