Wet and Dry Rot

Fungal decay can affect buildings of all ages, and if decay is discovered it should be identified and remedial action taken without delay. Fungal decay occurs in timber which becomes wet/damp over a long time, resulting in the attack by one of a number of wood-destroying fungi.

There are two forms of fungal decay: Brown (dry) rots and White (wet) rots.

  • Brown rots feed on the cellulose and hemicellulose content of the wood cell structure, resulting in a cuboidal surface forming on the timbers.
  • White rots feed on the lignin, cellulose and hemicellulose content of the cell structure, resulting in the timbers becoming stringy.

The most well-known one being referred to as Dry rot is Serpula lacrymans and wet rot is cellar fungus i.e. Coniophora puteana or mine fungus i.e. Poria vaillantii. There are many others but these are less common and are normally confused with one of the above.

Dry fruiting body

Dry rot

Dry rot Serpulala crymansis is considered the most severe form of fungal decay to affect a building. It can spread unseen behind, over and through masonry to infect and affect the structural integrity of larger timber sections within a building. To effectively eradicate dry rot requires a specialist CSRT-qualified timber surveyor, who understands the nature of the fungus, the growth patterns and the environmental requirements for the fungus to become established.

Wet rot affected floor joists

Wet Rot

There are hundreds of wet rot species, the most commonly found in buildings being cellar fungus Coniophera puteanait which has the potential to cause substantial structural damage to timbers. It tends to be more localised to the moisture source than dry rot.

Timbers affected by wet rot have a high moisture content, which is normally from a building defect, allowing a readily available source of moisture i.e. a plumbing defect, or timbers being in direct contact with damp masonry or in an unventilated void, resulting in high levels of condensation forming.

Our surveyors and technicians are highly qualified and experienced in identifying dry and wet rot fungi growth.

Fungal decay only occurs in wood with a moisture content of 20% and over. Finding the source of dampness, eliminating moisture ingress, and promoting drying is most important and always necessary.

Outbreaks of fungal decay always start similarly: the mature fruiting bodies of wood-destroying fungi that develop during an attack produce millions of microscopic spores widely dispersed by air currents. Where they fall on untreated damp wood, they germinate by pushing out a hollow tube called hypha into the damp timber, which grows and branches to develop a mass of threads called mycelium.

The mycelium develops inside the timber and breaks down the wood for food. The wood may darken in colour and develop a characteristic cracked appearance, and some wet rots may bleach the wood (white rots). Eventually, the wood loses its strength and, in some situations, may become dangerously unsafe.

The main differences between dry rot and wet rot are the degree of development of mycelium on the wood surface and the ability of the fungus to spread into other timbers via adjacent masonry. The two types of decay must be correctly identified since they require different treatments.

Think you have a dry rot problem – book a professional survey today for peace of mind.

Patterns and providing specifications to eradicate the infection correctly.

A fully insurance-backed guarantee covers all remedial works to eradicate dry rot.

Building and property wet and dry rot treatment services in Manchester, Salford, Stockport, Cheshire, Saddleworth, High Peak Derbyshire and Glossop.

Would you like to talk?

If you have any questions, please call our Oldham office on 0161 633 9860 or our Wilmslow office on 01625 900 800, or fill in the contact form, and we will be happy to answer any of your questions or plan an inspection. (Inspection appointment refunds are subject to a Minimum 24hr cancellation notice.)