Damp and moisture meters
Can water dripping from a ceiling be condensation in the loft rather than a hole in the roof?
Yes. The Building Research Establishment has reported that drips into rooms are often condensation that has built up in a cold roof void, not a leak, even when they show up in bad weather. A home survey should separate what it saw on the covering from what it saw on the underside of the felt.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
BRE’s note is plain: water vapour can enter a cold roof faster than it is ventilated out, then run down and drip. The clues in the loft are wet felt, droplets on the underside, damp insulation and staining that does not line up with a slipped tile. The fix they describe is either a vapour control layer on the warm side of the insulation or ventilation on the cold side. That is not a new roof covering.
A surveyor who could enter the loft can record those signs and still not prove which mechanism dominates on a dry day. RICS home surveys are visual. They do not run a condensation calculation. If the rating is about the ceiling stain, ask whether the felt was wet, whether eaves vents were blocked, and whether any tile was actually out of place. Do not accept a strip-and-retile quote for a ventilation problem.
What should you ask your surveyor?
- Was the underside of the felt wet, or did you see daylight through a hole?
- Are the eaves vents open, and how thick is the insulation against them?
- Does the ceiling stain sit under a joint in the roof, or under a cold patch of loft?
What are the typical next steps?
- Do not book a full re-roof because of drips until someone has looked in the loft.
- Photograph the felt, the insulation and the eaves before anyone lifts tiles.
- If you need a cause, ask for a roof inspection that will say whether this is ventilation, a covering defect, or both.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
Does BRE say every drip is condensation?
No. It says drips are often condensation rather than the leak people first suspect. A real hole still exists. The point is not to assume the covering has failed.
Will more insulation alone stop the drip?
Insulation without a path for vapour can make a cold void wetter. BRE points to vapour control on the warm side or ventilation on the cold side, not to a thicker quilt stuffed into the eaves.