Failed lead flashing
Most roof leaks are not holes in the roof — they are failures where the roof meets something else. Lead flashing at a chimney, abutment wall or valley is the usual culprit, and it fails long before the surrounding tiles do.
What it looks like from above
- Lead lifted or peeled back at the upstand, with a visible gap into the joint
- Cracks and splits along a fold line where the lead has fatigued
- Missing or crumbling pointing where the flashing is chased into the wall
- Patches of roofing compound or mastic from an earlier temporary repair
What happens if it's left
- Water tracks along the timber and appears as a ceiling stain some distance from the actual entry point
- Persistent damp in the chimney breast and salt staining on internal plaster
- Failed patch repairs mask the problem while the timbers below keep getting wet
How it's normally fixed
Stripping the failed lead and re-dressing a new code-appropriate flashing, re-chasing and re-pointing into the masonry. Mastic and flashing tape are temporary at best.
Common questions
Why does the ceiling stain not line up with the leak?
Water entering at a flashing runs along the underside of the roof timbers before it drips. That is why locating the entry point from inside is unreliable and photographic evidence from above is so useful.
Is roofing mastic a real repair?
It is a stop-gap. It buys a season or two and then cracks. If a survey shows several mastic patches, the flashing has been failing for a while.
Think you've got this on your roof?
We photograph every elevation, circle each defect and grade it by severity — £99 residential, £149 commercial, report within 24 hours.