Plumbing advice · Seasonal & Prevention
Damp, Mould and Your Plumbing
When black mould is a leak, when it is condensation, and how to tell before spending money.
Leak or condensation?
Mould in a cold corner of an outside wall or around window reveals is usually condensation. A defined damp patch that grows regardless of season, especially on an internal wall or ceiling, is water from somewhere, and that somewhere is often pipework.
The plumbing culprits
Weeping joints inside voids, failed shower sealant, a slow toilet pan leak, or a heating pipe under a solid floor. The meter test and a moisture map find them without opening anything speculatively.
Why speed matters
Mould spores affect breathing, and structural timber that stays wet rots quietly. If a damp patch survives two weeks of ventilation and heating, stop redecorating over it and get the source found.
Need it done instead?