Dry Rot Guide

Serpula lacrymans Rot


  • Mycellium: silky white sheet and cotton wool-like cushions with lilac yellow tinges.
  • Fungal strands are white to grey and brittle when dry.
  • Sporophore: fleshy pancake or bracket – rusty red when mature.
  • Spores: bulk spores are a reddish brown dust.


Decay fungi are living organisms which send minute threads called hyphae through damp wood, taking their food from the wood as they grow.


It most often occurs in damp timber which is in contact with, or embedded in, wet brickwork or masonry. Symptoms are: timber cracking, fruiting bodies, red dust or an acrid mushroom smell. It has been known to transport water up three storeys of a building to an area where decay is occurring.