Wet Rot Fungi

More common than dry rot, wet rot is caused by a fungi from Coniophora genus. They need wet timber with moisture contents from 30 to 90% for a long time. According to literature, the optimum is around 45%. The genus Coniophora (Coniophoraceae, Boletales) comprises about 20 species occurring worldwide with a broad host range primarily on conifers. Seven species occur in Europe and five in Germany. Coniophora puteanais frequently associated with brown-rot decay in European buildings.

Wood with wet rot has a typically soft and spongy feel and often looks darker than surrounding healthy wood. If the wood is painted it can mask the decay and appear quite healthy; it’s only by poking with a screwdriver you’ll discover if it’s affected. On walls the fungus manifests with brown/black strands in a fern-like pattern.