Wet Rot and Dry Rot: Understanding The Differences

Wet rot is a type of wood-destroying fungus that thrives in conditions with high moisture and dampness. This fungal infection causes timber to weaken, disintegrate, and change color, which can be either lighter or darker. Even after the timber dries out, the damage remains, leaving the wood weak and flaky. Wet rot typically stays localised to the damp area, which makes it somewhat easier to treat. However, if neglected, it can lead to significant structural damage. Common types of wet rot include Cellar fungus (Coniophora puteana), Mine fungus (Poria vaillantii), and Phellinus contigus.

Dry rot, while less common, is a more serious fungal issue that attacks timber in buildings. It flourishes in damp, poorly ventilated spaces, like under floorboards or behind paneling, often making it difficult to detect. Unlike wet rot, dry rot can rapidly spread beyond its initial moisture source, even through thick walls, in search of more timber to consume. Signs of dry rot include mushroom-like fruiting bodies, grey-white hyphae strands, a ‘cotton wool’ appearance when strands clump together, large cracking, color changes in the wood, and timber becoming weak and brittle. Due to its aggressive nature and potential for widespread damage, dry rot requires expert intervention for treatment.