Damp patch on the ceiling: leak or condensation?
Getting this right matters, because the two fixes are completely different. A ventilation problem treated as a leak means paying for roof work that changes nothing.
Water coming in right now? We prioritise active leaks across Hampton, Twickenham, Teddington and the wider TW and KT postcodes.
Call 07748 750711A leak follows the rain and makes one defined stain with a tide mark. Condensation shows up in cold, still weather, spreads across a wider area with no clear edge, and is usually worst in the coldest corners of the ceiling.
The timing test
Track when the patch darkens. Worse during and just after rain means water ingress. Worse on cold, dry mornings, or in a bathroom or kitchen ceiling, means condensation.
The shape test
Leaks make a defined stain, often brown, with a ring or tide mark where the water dried. Condensation is paler, softer edged, and frequently comes with black spot mould rather than a stain.
The loft check
Go up on a bright day with the light off first and look for daylight through the covering. Then with a torch, look for wet timber directly above the patch, damp underlay, or droplets on the underside of the felt. Widespread droplets across the whole loft is condensation.
What causes loft condensation
Warm moist air from the house rising into a cold loft with nowhere to escape. Modern insulation over blocked eaves, bathroom fans venting into the loft instead of outside, and sealed up old roofs with non breathable felt are the usual reasons.
What each fix involves
A leak means tracing and repairing the entry point, often flashing or a tile. Condensation means restoring airflow: eaves vents, tile or ridge vents, ducting fans properly to outside, and keeping insulation clear of the eaves gap.
FAQs
Yes, and it is common on older properties. We look at both while we are there rather than fixing one and leaving you with the other.
The stain will dry, but the cause has not gone. If the timber above it is staying damp you get rot and, eventually, ceiling failure.
On site quotes are free across our coverage area, and that includes telling you when the answer is ventilation rather than roof work.
Related reading
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