Dry Rot / Wet Rot

BUILDING PATHOLOGY, ACQUISITION SURVEYS

[Serpula Lacrymans | Coniophora Putean]

Dry Rot and Wet Rot are forms of fungaldecay which typically manifest in timberelements of a property and can causeserious damage and require very costlyrepairs.

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Dry Rot

Dry Rot is caused by the fungus Serpula Lacrymans and is a highly destructive form of wood decay. The fungus develops most readily where timber elements have been exposed to moisture and there is insufficient ventilation to allow them to dry.

This can often be the case in suspended timber floor structures, or in roof voids, only requiring a relatively small amount of moisture to allow the issue to get very serious, with the fungus germinating and spreading well beyond its original source. Dry Rot can also spread to other materials other than wood, including masonry and brick surfaces.

Dry Rot causes significant decay to timber elements, causing them to weaken and eventually fail completely.

Dry Rot first appears by a darkening of the area of affected timber. Over time, mycelium (the fruiting bodies) will emerge, typically as white strands with the appearance of cotton wool. In more extreme cases, large brown or ‘rusty’ appearing growths may form.

Building surveyors need to be particularly live to the signs of Dry Rot, including the distinctive musty smell, likened to the smell of mushrooms.

Wet Rot

Wet Rot is typically caused by the fungus Coniophora Putean. Wet Rot occurs in areas affected by water ingress (e.g. failed roof coverings or poor weatherproofing, etc).

Although generally less destructive than Dry Rot, Wet Rot can still weaken structural timbers and cause extensive damage if left untreated.

Affected timber will generally begin to show cuboidal cracking, and then dark brown or black fungal threads will appear on the surface.

In some cases, a form of Wet Rot called White Rot will be present, causing the wood to take on a paler colour.

Early Diagnosis

Affected timbers may be salvageable upon early diagnosis – and the root cause being eradicated.

Sometimes partial timber replacement or fixes can be implemented, but in many cases, significant replacement and rebuilding may be necessary.