Decay Fungi or "Rot" & "Dry Rot"
Wood products used in the construction of a home are susceptible to decay or "rot". However, if the materials are properly maintained, they can last for hundreds of years.
Wood rot is caused by the attack of three basic types of fungi:
Stain and mold fungi mainly grow on the surface of the wood causing discoloration. By themselves, they do not weaken the wood, but their presence does indicate a moisture problem exists and warns of conditions which are favorable for the growth of the decay fungi. Decay fungi are microscopic threadlike plants that grow in the wood and attack the wood's cellular makeup.
Physical changes in the wood may sometimes not be apparent on the surface. The changes can be detected by probing the wood with a screwdriver or ice pick. If the wood is in good condition the probe will not penetrate much farther than the surface. If the wood has deteriorated the probe will easily penetrate into the wood.
Wood that has been attacked by the decay fungus may be discolored, white and spongy or brownish and crumbly. The decay greatly reduces the strength and structural integrity of the wood. In the final deterioration stage the brownish crumbly rotted sections are often very dry. Some people will refer to this stage as "dry rot".
Gordon L. Smith
Home Inspector / Contractor
BTR# 50280 • ROC# 269134