Dry rot has a deceptive name. It is actually caused by the fungus Serpula lacrymans and requires moisture to thrive. Dry rot affects a home’s wooden structure and causes expensive structural damage. The dry rot will use the wood as a source of food, spreading as it breaks down the wood and destroys a home. The fungus can also use inorganic materials such as concrete as a way to spread and infect other areas of a home. The distinct stages of dry rot can be identified.
Look for an area in a home's timber structure, such as the floor joists, floor boards and skirting boards, that appears to be covered in white cotton wool and is dripping water. This is the first stage of dry rot if it is growing in a damp, humid environment. Dry rot fungus that is forming in a drier setting will appear gray with patches of yellow that have a purplish tint. This stage of dry rot can also be seen on concrete or brick near the initial infestation.
Watch for developing fungus that is ready to reproduce and spread even farther; it will have a brownish coloring and the appearance of a baking pancake with spores. Many times this stage of dry rot will begin to creep through plaster as well.
Watch for timber affected by dry rot to become dark brown and dry. This is occurring because the fungus is stealing all the water from the wood. Cracks will also begin to form along the length of the timber, and it will easily pull off and break apart with bare hands. This can make the structure a dangerous place to inhabit.
Inspect the entire home for dry rot once it has been identified in a single area. Pay attention to places in the home that are not easily visible, such as the underside of wooden floors or behind door frames. Poke through floor joists in the basement with a screwdriver as well. If the screwdriver easily enters the wood, it is already affected by dry rot.