All You Need to Know about Wet Rot

There are many different ways in which timber can be affected, making it unsound and in need of replacement or treatment. These include Dry Rot, Wet Rot, or Woodworm; here we focus on Wet Rot.

What is Wet Rot?

The most common type of wet rot is caused principally by Coniophora puteana. Poria vaillantii is another important wet rot fungus, and a number of less common fungi also occur.

Coniphoria can be found in some form in most properties. Within timber, the higher the moisture content the higher the chance of wet rot decay.

While each fungus has its own unique features, the general appearance of wet rot is similar – as is the treatment. Wet rot is typically confined to the area of dampness because the mycelium does not spread into walls.

Wet rot is not as destructive as dry rot, however can and does cause structural damage.

Signs of Wet Rot in Timber Floors

Wet Rot decay is usually first identified when floor timbers start to bounce or have movement.

Skirting boards affected show signs of cracking even through paint. The unpainted unprotected rear of a skirting board will be more vulnerable to wet rot decay.

How To Prevent Wet Rot

To prevent wet rot it is advisable to ensure that all timber, including window and door frames, are well painted/protected from rain water.

Ensure that all gutters and downpipes are free from defects or leaks. Ensure that sub floor ventilation is adequate and unblocked as poor ventilation will contribute greatly to any timber decay problems.

Ensure any new timbers introduced to a building are isolated from masonry by the use of a physical membrane.

Causes of Wet Rot

Unprotected timber in direct contact with moisture.

Wet rot can affect any unprotected timber and joinery so regular maintenance is very important.

Insufficient ventilation below suspended floors.

Possible leaks from pipes and domestic appliances.


Dean Webster, company director and CSRT surveyor, visits each property to inspect the areas of concern. Clients are provided with a detailed report on all findings, treatments available, and a breakdown of costs should any remedial works be required.

As a specialist timber contractor you can be assured of the problem being correctly diagnosed and a suitable specification of works being provided to resolve the timber problems.

Our surveyor would ensure that the source of the moisture ingress that caused any issues were established and if defects found they are identified in the report so that they can rectified.

No timber treatments are required for an outbreak of wet rot The decayed timber would be removed and if required replaced with pre-treated timbers.

A long term guarantee would be provided for these specialist timber works.

Recommended Sources for Further Reading on Wet Rot

Property Care Association

Take a look at the following page for a wealth of information –

Mr Graham R Coleman B.Sc (Hons)., M.I.Biol., C.Biol., A.I.W.Sc., F.Inst.S.S.E.

For more in depth information about rot in timber read the “Know your wood rotting fungi” by the industries leading expert who has written many technical publications and articles-

Find Your Answer from our Surveyor

Find your question on our Ask the Expert page where our Director Dean Webster has tried to answer all our FAQs!