13 Feb Diagnosing and Investigating Damp
It’s important to inspect your property for damp on a regular basis. Start by checking your roof during wet weather if you observe damp patches on the ceiling.
If you notice any slates or tiles on the ground after a period of particularly windy weather, or can see daylight inside your loft it’s likely that your roof is in need of repair.
Problems with rainwater fittings may become evident during heavy rain. Staining to exterior walls and plant growth can also indicate that your parapets, gutters and ground level gulleys are in need of attention.
Look out for condensation; it appears as tiny beads of water on shiny, hard surfaces, presents as mould on interior finishes, and is unrelated to wet weather conditions. Penetrating damp however, usually appears after periods of heavy rain and is a result of hairline cracks in inadequate cement pointing and rendering. Rising damp can extend up to 900mm above the level of the floor and leaves a tidemark on finishes; salt sometimes also appears as a white deposit.
If you have a water meter installed and notice that your bills have increased dramatically, or if you have a tank that is constantly refilling this may indicate a leak.
Checking for signs of damp is relatively straightforward, but sometimes scientific analysis may be necessary. Tests include on-site moisture testers, capacitance meters, and the use of electrical resistance. Care however, must be taken when clarifying results. Sometimes damp is diagnosed due to high electrical moisture readings which may occur as a result of the presence of salt from a previous damp problem, penetrating damp or continued condensation. Unfortunately, surveyors often pass high meter readings on to damp proofing contactors who have a vested financial interest and who encourage over specification. To find out the exact cause of a damp problem continued monitoring is often necessary.