Dry rot is the term given to brown rot decay that deteriorates timber in buildings and other wooden construction sometimes seemingly without an apparent source of moisture. Dry rot is an extremely serious problem and if it is seen in your home or working place it is very important to remove it as soon as possible. Dry rot fungus can pull moisture from moist areas such as the foundation to dry areas. Dry rot has the ability to grow over and through materials from which it obtains no nutrients, e.g, soil, plaster, mortar. Dry rot is caused by the fungus, Serpula lacrymans.
Serpula lacrymans develops extensively on the surfaces of infected timbers and in still, humid conditions the fungus produces a mass of cotton wool-like growth. Serpula Lacrymans prefers temperatures between 21-22o celsius.
Wood members which are heavily damaged by dry rot should be cut out and replaced. You should always cut out damage at least one foot beyond the rotted areas. Wood with dry rot can attract pests such as termites. Moisture control is the key to preventing wood decay fungi from causing rot.
The commonly held view of an outbreak of the dry rot fungus (Serpula lacrymans) within a building is that it is an extremely serious infestation that is hard to eradicate and requires drastic remedies. One interesting feature of dry rot is that the wood is often decayed internally with a very thin surface veneer of sound timber being left.