Rising Damp in Bedford

What rising damp actually is

Rising damp is moisture from the ground rising up through the structure by capillary action, where there is no effective damp-proof course, or where the existing one has been bridged or has failed. It is typically found low down on ground-floor walls and often leaves a characteristic band of staining and salts.

Typical characteristics

• Low-level dampness, generally to around a metre
• Capillary movement of moisture through the masonry
• A damp-proof course that is missing, bridged or failed
• Hygroscopic salts drawn from the ground into the plaster
• A tide-mark or band where the moisture reaches its height
• A distribution of moisture consistent with ground contact

Why low-level moisture is not automatically rising damp

Damp at the base of a wall can equally be caused by high external ground levels bridging the DPC, a rendered-over air brick, a leaking downpipe, condensation collecting on a cold surface, or a plumbing defect. Each of these mimics rising damp but needs a completely different remedy.

This is why proper investigation matters. Diagnosing rising damp — and injecting a chemical course — when the real cause is a leaking gutter simply leaves the problem in place.