Damp and moisture meters
Can a cold spot on a ceiling be missing loft quilt rather than a leak?
Yes, a cold spot, sometimes with a faint mark or a little mould, can be a gap in the loft quilt rather than water from the covering. The tiles may be sound. If the loft was entered, a bare patch of ceiling can be seen, but quilt hidden under full boarding cannot.
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?
Insulation works where it is present. A gap at a hatch, around a downlight, or where a roll was never laid leaves one cold patch. Room air drops moisture on that cold plaster. The mark is often pale mould or a grey spot, not a brown rain stain, and there may be no mark in the loft above it at all. A leak leaves a more obvious trail on felt or timber. The surveyor who can see both the ceiling and the loft should compare them before calling the covering failed.
Boarded lofts hide the quilt. Stored goods hide it too. The inspection does not lift boards as standard and does not guarantee what is under them. If the loft was not entered, a cold spot is unexplained. Do not buy a new roof for a single cold patch that lines up with a gap you can see in the quilt. Lay insulation over the gap, keep eaves paths clear, and separate that job from any real roof defect the report has also named.
What should you ask your surveyor?
- Did the cold spot line up with a gap in the quilt?
- Was there a rain stain on the felt above it, or a bare ceiling and dry felt?
- Was the loft boarded so the quilt could not be seen?
What are the typical next steps?
- Do not reroof because of a cold ceiling spot that matches a gap in the quilt.
- If the loft was boarded, accept that the quilt under the boards was not seen.
- Keep a genuine roof stain, if there is one, as a separate sentence.
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
Can downlights make a cold spot?
They can interrupt the quilt. The survey may not move insulation around fittings. Say if that area was not seen.
Is mould on that one spot a health verdict?
It is mould on a cold patch. The cause to check is the missing insulation or a leak. The survey is not a medical opinion.