Roofs and flat roofs
The lead valley is split along one welt. Does that split condemn the tiles on both adjoining slopes?
Only the split along one welt is the lead-valley defect, not a verdict on the tiles of both adjoining slopes. A welt is a folded joint in the lead. A split there is a failure in that sheet, on that line. The tiles or slates that shed into the valley are a different material, and this visit does not condemn them because the metal has opened. Read the note against the valley lead. Keep each slope's covering as its own question.
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?
Valleys collect water from two slopes and hold it in the metal. A split on a welt can let that water through onto the boards even while the tiles on either side remain whole and in course. Redressing the lead is not the same job as stripping both pitches. The survey records the split it could see. It does not grade every tile that drains toward that joint.
Ask the roofer to describe the welt, the length of the split, and whether the lead can be repaired or needs a new length. If both slopes sit inside the same figure, make them say why in writing, rather than assuming the split has ended the covering. One damaged joint is not a re-roof. Leave the tiles out of the valley price unless a separate defect is named.
What should you ask your surveyor?
- How long is the split, and is it confined to one welt?
- Did you see the tiles on each adjoining slope slipping, or only the lead opened?
- What should a quotation name if it is truly about this valley and not the pitches?
What are the typical next steps?
- Photograph the split welt before leaves or a repair hide it.
- Obtain a quotation that describes the lead valley on its own.
- Do not accept a price for both slopes as the answer to one welt.
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 split welt mean both slopes must be stripped?
No. The split is in the lead joint. The tiles on the adjoining slopes are not condemned by that opening on its own.
Is the valley board automatically rotten because the welt has split?
Not on this note. The defect named is the split in the lead. The board beneath it is a separate question if it was reached at all.