Roof lead flashing is a piece of lead sheet or foil used to create a watertight seal at roof junctions, penetrations and other vulnerable details. Lead has been one of the most reliable roofing materials for centuries, thanks to its exceptional durability and malleability.
Why lead?
Lead has several properties that make it ideal for roof detailing:
- Malleability — lead can be easily bent and shaped to fit irregular surfaces such as brickwork and roof tiles
- Longevity — properly installed lead flashing can last 50 to 100 years
- Weather resistance — lead withstands UV radiation, rain, frost and heat
- Self-healing — lead forms a protective patina that seals minor scratches
Application
Lead flashing is used at various points on a roof:
- Chimney abutments — around the junction between a chimney and the roof surface
- Roof windows — along the sides and top of skylights and roof windows
- Wall abutments — where a roof meets a rising wall
- Roof penetrations — around ventilation pipes and other services
- Dormers — at the junction between dormer cheeks and the main roof
Lead alternatives
Modern alternatives to lead include self-adhesive flashing tapes made from plastic or aluminium with a butyl adhesive layer. These are lighter and easier to install, but generally have a shorter lifespan than traditional lead.
Related terms
- Roof penetration
- Roof covering
- Dormer
- Roof sheathing
- Waterproofing
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