Serpula (fungus) cover the surface they are growing on (known as the substrate). The hymenophore, or spore-forming surface, generally has a wrinkled appearance. The species grow on, and digest, mainly coniferous wood, causing a process known as brown rot. One species, dry rot ("S. lacrymans"), is a highly destructive agent of houses. Damp structural timber is an ideal substrate for the germination of "Serpula" spores. The fungal hyphae penetrate the wood and release enzymes that break down structural polysaccharides such as cellulose. There may be no external indications that the fungus is present until the rot is far advanced and fruit bodies
Serpula lacrymans needed to promote "Serpula lacrymans" growth. In terms of aeration "Serpula lacrymans" often grows near ventilation shafts which shows a preference for concentrated oxygen. A moisture content of 30 to 40 percent is its ideal level in wood to promote fruit body formation. It appears that "Serpula lacrymans" requires an environment where both inorganic and organic materials are present. The fungus uses calcium and iron ions extracted from plaster, brick, and stone to aid the breakdown of wood, which results in brown rot. Although it is a common indoor biodeterioration agent, it has only been found in a few natural