Why Is My Ceiling Leaking?
The five most common causes of ceiling leaks in UK homes — and how to find the source before the ceiling collapses.
A wet or stained ceiling is nearly always caused by one of five things: a bathroom above, a flat roof, a pitched-roof defect, a central heating pipe, or condensation in the loft.
Bathrooms are the number one culprit. Shower trays, sealant failure and waste pipes are the usual suspects. A single failed seal can drip for months before staining shows through.
Flat roofs — especially over extensions and dormers — are the next biggest cause. UV degrades felt and EPDM; ponding water finds the weakest lap and follows the joists inside.
Pitched roofs leak at flashings, valleys and slipped tiles. Water can travel several metres along a rafter before showing.
Central heating pipe leaks are often the hardest to find. If your boiler keeps losing pressure and the ceiling below a radiator is wet, that's your answer.
Finally, cold loft condensation on the underside of felt can drip like a leak. Thermal imaging tells them apart in minutes.