Roofs and flat roofs
What should you ask if the lead on a flat roof has split along a roll?
Ask whether the split follows a roll or a drip, because traditional lead flats are joined over timber rolls and the metal often fatigues where it is folded and fixed. That split is a break in the sheet, not a comment on every bay. From a window or the ground a surveyor may see an open split and miss a hairline, and they cannot measure how much thickness is left.
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 roll is the raised joint between sheets, not a decorative ridge. Water should run off the roll into the bay. When the lead cracks along the top or at the fixing, rain gets into the timber roll and then the deck. Patches of mastic over the crack are a clue that someone has already chased the leak. A home survey records the split if it was in sight. It does not lift adjacent sheets to map every crack.
Leadwork is priced by the piece that has failed, the access, and whether the timber roll is rotten once opened. There is no RICS rate for a bay of lead. Do not replace the whole flat because one roll has split, unless a roofer who has been up there finds the other rolls the same. Do not confuse this with a lead valley on a pitched roof. Ask the surveyor which roof and which roll.
What should you ask your surveyor?
- Which rolls did you see, and which were out of sight?
- Is the split open, or only a crease in the lead?
- Did you see the deck, or only the sheet?
What are the typical next steps?
- Ask a leadworker to look at the split roll before you budget a new flat roof.
- Do not rely on a mastic smear as a repair.
- Keep bay roofs and main lead flats as separate items if the house has both.
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 crease the same as a split?
No. Lead creases as it moves. A split is open. The survey should not call every wrinkle a hole.
Does a copper or zinc roll get the same comment?
Only if that is the metal on this roof. Do not rename it lead. The fatigue point can be similar. The survey names the metal it saw.