Roofs and flat roofs
A crack in a fibreglass covering runs into the upstand. Has that joint been water-tested?
No. That joint has not been water-tested. A crack in the fibreglass runs into the upstand, and the survey saw the crack. Seeing it is not a hose test of the joint. The upstand is the turned-up edge of the covering. The crack meeting it means the break arrives at that detail. The visit records the line of the crack. It has not shown how much water passes, and it has not shown that the joint stays dry.
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?
A fibreglass flat roof depends on a continuous skin. A crack is a break in it. At the upstand, the break meets the turn-up against the wall or curb. Rain can follow a crack while the rest of the deck looks whole. Without a water test the survey will not invent a leak and will not clear the joint. A dry day does not answer it. The point is an untested crack where the covering turns up.
Tell the solicitor the crack runs into the upstand and was not water-tested. A contractor used to this covering can assess and repair the joint. The survey has not instructed that work. If a guarantee names the fibreglass, ask whether the crack still falls within it. Do not tell a lender the flat was proved tight. No water test was done on the joint.
What should you ask your surveyor?
- Does the crack die at the upstand or pass through it?
- Was there staining on the ceiling under this joint?
- What test would show if water uses the crack?
What are the typical next steps?
- Report the crack into the upstand as seen, not as water-tested.
- Ask a contractor familiar with fibreglass roofs to assess the joint.
- Do not describe the flat as proved dry.
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 the crack already show how much rain enters?
No. The survey saw the crack run into the upstand and did not measure a leak. There is no timed test and no quantity of water. A visible crack is a break in the covering. What it lets in is unproved until the joint is tested or opened. The report stops at the crack that could be seen.
Is fibreglass the same build-up as lead sheet?
No. Fibreglass is a laid membrane. Lead is metal worked over rolls and drips. The survey has not treated them as one roof. This finding is a crack in fibreglass running into an upstand, and that joint was not water-tested. Another covering elsewhere would be a different defect. Do not move this crack onto lead.