Why valleys fail and how they are rebuilt
A valley is where two slopes meet and it carries water from both, so it works harder than any other part of the roof. Old valleys wear thin, collect moss and leaves, and get patched again and again. Once the lining fails, water runs under the tiles on both sides and shows up inside, often well away from the valley.
A rebuild strips the valley back to the rafters, lays new membrane through it and fixes new battens either side, ready for the new valley lining and the tiles to go back. See our roof repairs service and the roof repair cost guide.
Signs your roof needs similar work
- Stains on a ceiling below where two roofs meet
- Moss and debris built up in the valley
- Old patch repairs along the valley line
- Tiles either side of the valley slipping