Roofs and flat roofs
A parapet gutter drains the flat roof and the outlet was not seen from above. What blockage has not been ruled out?
A blockage of the outlet has not been ruled out. A parapet gutter drains the flat roof and the outlet was not seen from above, so the sump, the downpipe head and any debris in that throat were not inspected. Parapet gutters are boxed channels at the edge of a flat roof. If the outlet blocks, water can rise over the covering or find a weak point in the lining. The survey recorded the gutter and the unseen outlet. It has not decided the outlet is clear, and it has not decided it is blocked.
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?
Flat roofs often rely on one or two outlets in a parapet gutter. You cannot judge that throat from the ceiling below or from the ground. Leaves, a slipped slate, or a crushed outlet cage sit where only a view from above will show them. This visit did not have that view. Ponding on the roof, if any was seen, was not tied to a proved blockage because the outlet itself stayed hidden. The limit is specific: the thing that lets the gutter empty was not inspected.
Ask a roofing contractor to look down into the outlet from the roof and to photograph it, as work beyond this survey. Tell your solicitor the parapet gutter's outlet is an access gap, not a clean bill. Do not tell a lender the flat roof drains freely because a downpipe was seen at street level. The head of that pipe, where the gutter lets into it, was not seen from above.
What should you ask your surveyor?
- Was the parapet-gutter outlet seen from above?
- Has a blockage of that outlet been ruled out or confirmed?
- Is a downpipe at street level being treated as a clear head?
What are the typical next steps?
- Treat an outlet blockage as not ruled out.
- Ask a roofer to photograph the outlet from the roof.
- Do not describe the flat roof as freely draining.
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 dry ceiling mean the outlet is clear?
No. A dry ceiling means no active leak was showing inside. It does not mean the outlet was seen, and it was not seen from above. A gutter can be partly blocked and still cope with light rain. The survey has not ruled a blockage out. A dry day is not an inspection of the throat.
Can the lining of the flat roof be passed while the outlet is unseen?
No. The survey has not passed the lining, and it has not seen the outlet that drains it. An unseen outlet is a limit on how water leaves the roof. Condition of the covering, where it was visible, stays a separate sentence. Do not merge a partial look at the felt into a statement that the roof drains.