Roofs and flat roofs
What is an abutment flashing, and can it leak while the tiles still look even?
An abutment flashing is the metal, usually lead, that weathers the joint where a roof slope meets a wall. It can crack, slip or pull out of its chase while the tiles on the slope still look regular. A tidy slope is not proof the joint is 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?
Water follows the joint, not the part of the roof you can admire from the pavement. A failed flashing often shows as staining on the wall or on the ceiling just inside that junction, sometimes only after wind-driven rain. A visual survey looks for a flashing that has come out, a chase that is empty, or a smear of mastic used as a temporary cover. It cannot see the soakers tucked under the tiles unless they are exposed.
Repointing the chase and dressing the lead back is a different job from retilling the slope. RICS home surveys do not price that job. If the report marks the abutment and not the tiles, do not let a quote rebuild the whole slope without explaining why.
What should you ask your surveyor?
- Which abutments could you see, and which were hidden by height or by a neighbour?
- Was the flashing lead, mortar, or a smear of sealant?
- Was there staining inside at that junction, or only a comment on the outside?
What are the typical next steps?
- Photograph the joint from the ground and any ceiling stain on the same day.
- Ask a roofer to price the abutment separately from the tiles.
- Do not mortar over a slipped flashing and call it a survey repair. Mortar is not lead.
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 cement fillet a proper flashing?
A hard fillet where lead should be dressed is a common temporary cover. It cracks as the roof moves. Ask whether that is what the surveyor saw.
Does a new tile slope include new flashings?
Not unless someone did that work. New tiles can sit against an old, split flashing. Ask what was replaced.