Regulated by RICS
When there are obvious signs of damp, a valuation/building surveyor has used a damp-meter to check the internal walls and is concerned there may be rising damp. It will be necessary to commission a damp report to determine the full extent of the problem, the cause and the level of work to rectify the issues.
Rising damp is the most common form of dampness. When moisture from the ground rises, by capillary action (rising against gravity) up through the wall or the ground floor slab, sudden action needs to be taken.
Treatment of rising damp will involve carrying out a small chemical damp proofing course. In some cases the ground floor slabs will need to be replaced and a damp proof membrane implemented. The comforting thing is that the majority of damp specialists offer a 30-year guarantee on their workmanship.
Dampness may also be caused by condensation, the occurrence of which is the responsibility of the inhabitants as opposed to an issue with the property. Lack of ventilation and using radiators for drying clothes is a common factor for this problem.
Wood Boring Insects (Woodworm)
Woodworm may manifest itself in a variety of wood ranging from three millimetres in size to 25 millimetres. Eggs are laid on or in the timber and the larvae that hatch feed and bore into the timber which consequently results in weakening of timbers and a risk to the structural integrity of the property.
Treatment of active woodworm involves applying insecticides to the timbers. In some cases the timber’s structural integrity has been compromised by the attack, and the replacement of the wood may be the only solution.
Fungal Decay (dry rot and wet rot)
Moist and damp conditions provide an ideal environment for a fungal attack. In cases where the moisture content is over 20 per cent this is classified as ‘dry rot’. Fine grey strands of fungus spread through wood and other materials, developing into sporophores. The spores expel, which in turn spread the fungus further. Timber suffering from dry rot becomes dry, brittle and begins to fracture to such an extent that it can be broken and crumbled by hand.
When the moisture content is higher than 30 per cent to 50 per cent this is classified as ‘wet rot’. The presence of wet rot in timber is recognised by a dark brown staining colour and splitting of longitudinal cracking.
Treatment of fungal decay is initially used to remove the source of the dampness which is enabling the fungus to ‘feed’ and develop. Exposure works will then be necessary to determine the full extent of the damage caused. Following any repairs or replacement works it will be important to treat the timbers with an approved fungicide to safeguard against recurrence.