Wood decay caused by the wood rotting basidiomycete Serpula lacrymans. The rotted timber is darkened and cracked into characteristic cubes. Dry Rot occurs in damp wood rather than wet wood and is particularly destructive because of the ability of the fungus to penetrate masonry in search of timber. Dry Rot has the ability to grow over and through non-nutrient materials, such as masonry, in its search for the timber on which it derives nourishment. The organism carries its own water which is used, together with self produced chemicals to dissolve the cellulose in the timber.
Growth rates can be dramatic, particularly in warm, humid and dark places.
These often land some distance from the initial outbreak as a greasy brown dust. Since individual spores are invisible to us, the presence of the deposit represents billions of viable spores, each capable of initiating a new outbreak. Spores can lay dormant for years and become active when conditions are favourable. Fully grown organisms can also become dormant if conditions change, only to reactivate when its preferred environment is restored. Prompt diagnosis and treatment is necessary to limit costly repairs.