Wet rot is a general term applied to many species of fungus, all of which will cause timber decay. These fungi can be divided into two groups: brown and white rots.
Instances of wet rot vary in severity of damage, but no wet rot possesses the ability to pass through inert material and spread to other damp timbers like dry rot. Thus, it is found in localised areas where it is exposed to considerable amounts of water ingress. Externally exposed timbers, timbers in contact with wet soil or masonry or timbers subject to a damp atmosphere can all suffer from wet rot.