Slate re-roof with lead valleys and a gable dormer

This roof had a gable dormer and a rear projection, so there were valleys where three roof slopes meet. The roof was stripped, re-slated in fibre cement slates, and the valleys were re-formed in lead with the slates cut in neatly on both sides.

Valleys are the weak point on complex roofs

A valley collects rainwater from two roof slopes and carries it down to the gutter, so it handles more water than any other part of the roof. Split lead, perished felt or badly cut slates in a valley are a common cause of leaks into bedrooms and loft spaces.

On this job the valleys were rebuilt in lead and the slates on each side were cut to a clean line. The photos show the slates being cut in, then the finished valley running down past the dormer.

Working around a dormer

Dormers add gables, cheeks and extra junctions, and each junction needs its own flashing detail. Re-slating the dormer roof at the same time as the main roof means the materials and fixings match and there are no mismatched joints left to fail later.

If your roof has dormers or rear projections, ask for the valleys and flashings to be priced as part of the re-roof rather than left as they are.