Roofs and flat roofs
The report cannot tell a warm flat roof from a cold one. Why does that matter before you treat a drip as a leak?
It matters because a drip can be a leak or built-up condensation, and the two are not the same job. The report cannot tell a warm flat roof from a cold one, so it has not decided which construction is overhead or which mechanism is wetting the ceiling. A warm roof places insulation above the deck. A cold roof places insulation below it, with a void that is meant to be ventilated. Dripping can be condensation rather than water coming through the covering. This visit has not claimed which roof this is.
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?
Treating every drip as a failed membrane sends you toward the covering when the moisture may be air from the room condensing on a cold deck. The reverse mistake is just as costly: dismissing a true leak because the ceiling looks like condensation. Without knowing where the insulation sits, and whether any void is ventilated, the survey cannot separate those paths. No test was invented here to force an answer. The report stops at the limit and at the drip.
Ask the solicitor for any drawing, guarantee or specification that shows the build-up, and keep that paper outside the survey. A roofing specialist can open a small area later if you instruct them, which is new work and not a method this report has prescribed. Tell a lender the construction is unknown and the drip is unexplained. Do not describe the covering as failed, and do not describe it as sound, on this visit alone.
What should you ask your surveyor?
- Has the visit established whether insulation sits above or below the deck?
- Is the drip being treated as a proved leak through the covering?
- Was any test laid down in the report for splitting condensation from a leak?
What are the typical next steps?
- Do not treat the drip as a proved leak.
- Ask the solicitor for any drawing or specification of the build-up.
- Tell a lender the roof type and the cause of the drip are unknown.
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 a stain on the ceiling identify the roof type?
No. A stain shows that something has wetted the ceiling. It does not show whether the roof is warm or cold, or whether the water is a leak or condensation. The report has already said it cannot tell those roofs apart. The stain stays a symptom. The construction stays unknown until papers or a later opening describe it.
Can ventilation of a flat roof be assumed from the drip alone?
No. A drip does not prove that a void exists, that it is ventilated, or that ventilation has failed. The survey could not tell a warm roof from a cold one, so those assumptions are not available. Do not add a vent layout the visit did not see. Any later check of ventilation would be a separate instruction.