What lead flashing does
Flashing is the strip of lead fitted where a chimney meets the roof, sealing the junction between two different surfaces so water can't get in through the gap. It's a small detail, but it's doing one of the most important waterproofing jobs on the whole roof.
Common causes of flashing failure
Lead work-hardens over time and can crack, especially at bends and joints. It can also come loose from the mortar joint it's tucked into, or corrode after decades of exposure. None of this is usually visible from ground level, which is part of why flashing failures often go unnoticed until they cause a leak.
Preventing roof leaks
Because flashing sits at a junction rather than a flat surface, it's a natural weak point — most chimney-related leaks trace back to failed flashing rather than the brickwork itself. Catching a flashing problem early is one of the most cost-effective repairs on a roof.
Lead flashing replacement
When flashing has failed, replacement is usually straightforward for an experienced roofer — cutting out the old lead and fitting new, properly dressed into the brickwork and roof covering. It's a specific skill, and flashing that's not fitted correctly will fail again quickly.
Protecting your roof from water ingress
Good flashing, properly installed, can last 50 years or more. If you've got a damp patch on a ceiling near a chimney breast, or staining in the loft close to where the chimney passes through the roof, flashing is one of the first things worth checking. Our leadwork team handles flashing repair and replacement across Bristol.