A DOBING & CO

For centuries timber has been used to construct buildings and will probably be used into the foreseeable future. One weakness of timber is that it is prone to attack by fungi and insects, especially under damp conditions. If left, this can result in critical deterioration of the wood and eventually failure within the structure of the building. There are two specific types of fungi provoke decay known as ‘wet rot’ and ‘dry rot’.

‘Wet rot’ is caused by excessive moisture from rain penetration through cracked layers of paint film or through faulty plumbing. A distinguishing feature of wet rot is prominent cracking along the grain of the wood. This type of decay is often found on window frames, facia boards, internal floors, and joists in contact with wet masonry. The eradication of such rot requires specialist remedial treatment.

Restricted ventilation and high humidity can lead to a condition of ‘dry rot’. Even when moisture levels within the wood are lowered the decay can still remain unless treated. Dry rot can cast easily from one part to the next and in older properties it can spread through porous masonry materials. Although the rot cannot significantly damage the masonry, once the rot is through it can then affect timber in other parts of the building. Red dust and cubical cracking are the signs of infestation. As with wet rot, eradication requires specialist remedial treatment.

Evidence of Rising Damp is easy to notice. It is represented by damp areas on walls usually within 1 metre of the ground level. It is caused by a capillary action of dampness rising from the ground up the wall through porous materials such as brickwork. Water drawn from the soil usually contains a low concentration of soluble salts. When evaporation occurs these salts crystallise out blocking pores in the brick, thus reducing evaporation, hence an increase in dampness.