Roofs and flat roofs
Can a split lead valley leak while the tiles on either side still look even?
Yes. A valley is the gutter-like channel where two slopes meet, often lined with lead. Lead can split or be dressed short while the tiles look orderly. Water then runs down the valley and into the roof instead of to the gutter.
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?
From the ground a valley is easy to miss, especially where it sits between a rear wing and the main roof. A surveyor with a decent view may see lifted lead, a temporary tape repair, or staining on the ceiling beneath. They will not always see a hairline split. The loft under the valley is the place staining shows, if it was inspected.
Leadwork is a specialist job. A tile quote that ignores the valley will not stop this leak. Ask the surveyor whether the valleys were visible. Ask a roofer or a leadworker for a written description before you negotiate. There is no standard price for a valley. Length, access and whether the surrounding tiles must come off all change it.
What should you ask your surveyor?
- Which valleys could you see, and which were hidden by the shape of the roof?
- Was there staining in the loft under the valley?
- Is any repair a tape or mastic smear rather than lead?
What are the typical next steps?
- Do not assume even tiles mean a dry valley.
- Get the valley named on any quote.
- If the loft was not seen, say that clearly when you rely on the report.
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 fibreglass valley lining the same as lead?
No. It is a different material. The surveyor should name what they could identify and admit what they could not.
Can moss in a valley be the whole problem?
It can block the channel. Clearing it is not the same as replacing split lead. Both can be needed.