Best known for destroying timber in buildings and ships and found in most parts of the world, Dry Rot (Serpula Lacrymans), is a wood destroying fungus that has the ability to travel through materials other than timber, giving it the potential to spread quickly. Therefore, where there is timber decay, identification needs to be made early on as to whether the cause is Dry Rot. Often, further measures, such as sterilisation of masonry will be carried out when dry rot is treated to prevent further spread. To avoid dry rot causing widespread structural damage, it must be treated quickly and correctly by an experienced company. With dry rot affecting timber with a moisture content of 20% and above, the removal of the source of moisture from the timber will be the core aspect of any treatment.
Typical indications of dry rot include:
- Wood shrinks, darkens and cracks
- A silky grey to mushroom coloured skin frequently tinged with patches of lilac and yellow often develops under less humid conditions. This ‘skin’ can be peeled like a mushroom.
- White, fluffy ‘cottonwool’ mycelium develops under humid conditions. ‘Teardrops’ may develop on the growth.
- Strands develop in the mycelium; these are brittle and crack when bent.
- Fruiting bodies are a soft, fleshy pancake or bracket with an orange-ochre surface. The surface has wide pores.
- Rust red coloured spore dust frequently seen around fruiting bodies.
- Active decay produces a musty, damp odour.
It is possible for timber to become damp and dry rot to appear for various reasons:
- Washing machine leaks
- Shower trays and baths
- Leaking roofs
- Rising damp
- Dampness penetrating through walls
However, with the source of damp removed and timber allowed to dry out, dry rot will eventually be controlled. It is important that infected timbers are removed and replaced with pre-treated timber, and any remaining timber is treated with fungicide. If the dry rot has passed through the masonry, it should be treated using masonry sterilisation.