Dry rot (Serpula lacrymans)


Property Remedial Articles - Olympic Construction

Dry rot (Serpula lacrymans) is a wood-destroying fungus that is found in most parts of the world. Although it affects forest timbers, dry rot is now best known for its ability to destroy timbers and buildings and is becoming more common by the day, due to poor workmanship and reduced ventilation.

Identification of Dry Rot It is important to correctly identify whether the timber decay has been caused by dry rot or another wood-destroying fungus such as one of the wet rots.

Dry rot fruiting body located on the ceiling of an incorrectly converted basement
This is because dry rot has the ability to travel through building materials other than timber, giving outbreaks the potential to spread quickly through a building. For this reason additional measures (e.g. masonry sterilisation and increased ventilation paths) often have to be taken when treating dry rot outbreaks over and above those necessary when dealing with outbreaks of other wood-rotting fungi. But the most important measure is to correctly identify the moisture source.


Dry rot can cause widespread structural damage, the remedial works required to eradicate dry rot correctly should be undertaken by a professional timber Treatment Company. Who are members of the Property Care Association PCA and hold a CSRT qualification.

The surveyor will undertake a full detailed survey to establish the source of moisture, extent of the dry rot outbreak and what treatments are required. He will also be able to advise you on the legal requirements and implications should the dry rot have affected the party wall and a neighbouring property.


The guarantee provided is just as important as both getting the survey and works undertaken right, Olympic Construction are able to offer GPI insurance backed guaranteeshttp://www.gp-insurance.co.uk/ on all works and are full members of both PCAhttp://www.property-care.org/  and Trust Mark http://www.trustmark.org.uk .

Dry rot affected timbers of a hallway floor due lack of ventilation and laminated floor covering

Dry Rot Control and Treatment

Timber can become damp for a number of reasons. Among the most common causes are leaking pipes and unventilated voids resulting in condensation. The dampness can also come from outside the building, for example, leaking roofs, rising dampness, or dampness penetrating through walls.
Dry rot in a floor void

Dry rot will only affect timber that is damp, typically affecting timber with a moisture content in excess of 20%. For this reason, removing the source of moisture should form the core of any dry rot eradication strategy.

Dry rot in a basement
Therefore, it is important that secondary measures are taken to defend against re-infection. Any affected timbers should be removed and replaced with pre-treated timber. Any remaining timbers at risk of being affected by the dry rot should be treated with an effective fungicide. Where the dry rot has passed through the masonry, it should be isolated using physical containment and/or masonry sterilisation.

Ventilation paths should be installed to ensure that the damp masonry dries down fast and importantly remains dry.

If you suspect fungal decay is affecting your property, don’t take the chance give us a call for free advice and peace of mind

Olympic Construction 0161-633-9860


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