Damp and Timber Building Survey for Rot and Woodworm

Building damp and rot

A damp and timber building survey is a common specialist report requested at London Building Surveyors, particularly when dealing with older buildings.

We recommend that whether you are buying a property (either a private or commercial premises) or taking a long lease on a commercial premises, a damp and timber survey is essential. It is crucial that you are both aware and fully understand the condition of any potential purchase or lease. This will help you to be mindful of any potential liability in regards to future repairs.

London Building Surveyors can carry out a full building survey on any property, however, we particularly recommend it for older properties, badly maintained properties, heavily altered properties and properties of non-traditional construction.

Damp Building Conditions


Damp conditions can lead to both rot and beetle infestations in timber, in fact beetle infestation can occur with even the smallest amount of moisture. In timbers that form an important structural component to your property is vital to act quickly if any defect is suspected. Structural elements made of timber can include roof timbers, timber lintels, floor joists etc. If left untreated beetle infestation and rot can very quickly result in timbers becoming fragile and structurally unsound. Here at London Building Surveyors we suggest that the quicker a problem is found and diagnosed, the easier and more cost effective it will be to find a solution.

We understand that seeing the words, damp, rot or woodworm on the results of a survey can be worrying and confusing. Only a qualified expert is able to identify damp and timber infestations in a building, you can trust London Building Surveyors to correctly diagnose any potential issues and provide guidance on solutions to treat any problems that may arise

Dry Rot in Buildings


Dry rot is caused by a certain species of fungi that digests parts of the wood, leading to decay and a loss of strength and stiffness in the afflicted piece of timber. Spores are transported through the air until they find the correct environment in which they can grow and flourish. Once established the fungus often leaves deep cracks across the woodgrain. This leaves the wood weak and brittle, and the cracks cause the wood to break easily. Often a white fungus (known as mycelium growth) can be seen on the surface of the wood, this can often be identified by the presence of white strands across timber and masonry. If the fungus is exposed to light it can have a yellowish tint to it.

Affected timber will crumble easily and be brown in colour. If left untreated dry rot can cause serious structural damage not only to timber as in some cases dry rot causes large mushroom like bodies that grow through plasterwork and masonry in order to reach fresh timber. London Building Surveyors frequently discover dry rot in concealed timbers. Often these timbers are in contact with damp brickwork which provides a suitable temperature and environment for the fungal spores to flourish.

Wet Rot in Buildings


Similarly to dry rot, wet rot is also found in timbers that are in contact with damp conditions, such as damp brickwork, however the spread of wet rot is very different to the spread of dry rot. Wet rot is caused by a fungus called ‘Coniophora Puteana’, which unlike dry rot remains confined to only the wet and damp areas of timber or plaster.

Any timber in an area where there has been a leak is likely to be affected by wet rot. With wet rot, a black fungus may appear on timber or plaster. Affected timber is likely to feel spongy and soft to the touch, it may also show signs of discolouration. Often a paint finish will be damaged and can indicate wet rot, however sometimes a paint finish can remain seemingly untouched, but there may be rotting from beneath. Once the decay has dried out it will cause the timber to crumble and crack easily. The appearance of both the timber and the fungus (mycelium) is similar to that of dry rot, hence the importance of using a trusted qualified surveyor, such as London Building Surveyors, to distinguish between the two.


Wood worm – Wood boring weevil – Pentarthrum Huttoni / Euophryum Confine


Woodworm in building wood


Wood boring weevils are often referred to as woodworms. They are normally found in timber that is damp and decaying. Wet rot provides the perfect environment, temperature and moisture content for woodworm to thrive. The woodworm larvae tunnel into the already weakened wood for between six months and a year. When fully mature the adult emerges by boring its way through the timber leaving exit holes. Often jagged markings are created on the surface of the wood where the woodworms have created tunnels in an attempt to break through the surface. Adult woodworm live for up to another year causing even further damage to the timber. Infestations can also spread to healthy wood. In the presence of a large infestation a fine gritty bore dust can often be seen. Woodworm can often be mistaken for the common furniture beetle, so it is important to get a fully qualified surveyor, such as London Building Surveyors to make a diagnosis.

Wood worm – Common furniture beetle – anobium punctatum


Common furniture beetles prefer hardwood timber and timber with a higher moisture content than is found in most wooden items in a typical home. They are often located in damp loft timbers, damp floorboards and on furniture where any polished finish has worn off. It is likely that any building with a woodworm problem is also likely to be suffering with excess damp and or wet rot. Common furniture beetles can also be found in areas with lack of ventilation, for example, a roof space or cellar. The bore dust of the common furniture beetle is very similar to the dust of the weevil, however it appears in more of a pellet shape. Timber affected by the common furniture beetle will be speckled with emergence holes measuring 1-2mm in diameter. Often the small hard shelled flying beetles may be found in properties afflicted with damp, particularly in bathrooms or by windows. At London Building Surveyors we understand that any beetle infestation can be devastating. Often the main outbreak is beneath the surface of timber so great care should be taken when walking on any timbers that have been infested as the timber will be incredibly weak and can easily fall through.

Contact London Building Surveyors


As previously noted, in some cases rot and beetle infestations can have very similar characteristics, however the severity and treatment can differ drastically and our staff at London Building Surveyors can advise you on this. One commonality, however, is that all rot and beetle infestations can cause timber to become structurally unsound. At London Building Surveyors we recommend that any damp, rot or woodworm should be investigated as soon it becomes apparent.

For an informal chat about your requirements please call 020 8257 5766 or you can contact us by clicking here.