lacrymans

Serpula lacrymans, commonly known as the dry rot fungus, is a basidiomycete that causes severe timber decay in buildings when moisture is present. It is the species most often associated with dry rot in temperate climates.

Description: The fungus grows as a cottony white to pale yellow mycelium on damp wood and can spread through timber and into adjoining materials. It forms yellowish-brown to cinnamon-colored fruiting bodies, often described as pancake-like shelves, which emit spores and a damp, musty odor. The organism decays cellulose and hemicellulose, leaving wood weak and crumbly.

Ecology and conditions: It requires sustained moisture in timber, typically above about 20 percent, and a warm, stable environment. It invades buildings with water ingress, poor ventilation, or damp basements, particularly older structures in temperate regions.

Lifecycle and spread: It spreads by spores and by networked mycelium that can extend through timber. Fruiting bodies appear when conditions are suitable, helping spread to new areas.

Management and prevention: Controlling dry rot centers on removing moisture sources, drying the affected area, and removing or stabilizing infested timber. Professional remediation may involve dehumidification, ventilation improvements, structural repairs, and treatments or replacement of decayed timbers.