Chimneys and parapets
Can a parapet wall let water in behind its flashing even when the pots look fine?
Yes. A parapet meets the roof at a flashing, often lead chased into the joints. If that joint opens, water runs behind the covering and down the wall, while the chimney pots, if any, are irrelevant. The leak is at the junction, not at the crown.
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?
Surveyors look for open chases, slipped lead, cracked copings and plants growing from the parapet. They may not see the back of the lead. A ceiling stain near the wall is supporting evidence, not proof of which joint failed. Copings without a damp-proof course under them can also let rain into the wall head.
Repair is leadwork and masonry, priced by a contractor who can reach it. Ask them to separate coping, pointing and flashing. A home survey will not lift the lead as standard. If the parapet is on a boundary, ask the solicitor before work starts. Do not combine this quote with a chimney-pot quote unless the same access really serves both.
What should you ask your surveyor?
- Which flashings at the parapet did you see, and were any open?
- Is the damp on the wall head, the ceiling edge, or the chimney breast?
- Could you see the coping and whether water can sit on it?
What are the typical next steps?
- Ask a roofer to quote for the flashing and the coping as named items.
- Do not reroof the whole slope because the wall junction is open, unless the slope itself has failed.
- Read the parapet-gutter question if the water is in a hidden channel rather than at a flashing.
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
Is a cement fillet as good as lead?
A smear of cement where lead should be is a common temporary repair. Surveyors often flag it because it cracks. It is not automatically equivalent to a proper flashing.
Do copings need a damp-proof course?
Many modern copings are detailed with one. Older walls may not have it. The survey should describe what it could see, not invent a detail behind the mortar.