Chimney leadwork and chimney flashing

Signs the leadwork around your chimney has failed

• A damp patch on the chimney breast or the ceiling beside it, worse after driving rain.
• Lead lifting from the brickwork or pointing missing along the step flashings.
• A back gutter behind the stack full of moss or split along its length.
• Sealant or bitumen painted over the lead, sometimes several layers of it.
• Staining on the rafters around the stack when you look in the loft.

A full chimney lead set, done properly

A chimney that sits in the slope of a roof needs four lead details working together:

1. Front apron, dressed over the tiles on the downhill face and turned into the brickwork.
2. Soakers and step flashings up each side: soakers under each course of tiles or slates and step flashings over them, cut to follow the brick courses.
3. Back gutter, a lead gutter on the uphill side, laid on a timber base, turning water around the stack. This is the piece most often done badly.
4. Correct laps and wedges, so every piece sheds water onto the one below and can move with the weather.

We strip the old lead and sealant, rake out and prepare the joints, form new lead to fit, wedge and point it, patinate it and photograph every side of the stack for you.

When it isn't the leadwork

Not every chimney leak is a lead problem and we'll tell you if yours isn't. Water can also get in through cracked flaunching (the mortar cap around the pots), open joints in the brickwork, an uncapped pot or through the stack itself where there's no working lead tray, a damp-proof course of lead built through the chimney. Condensation in a disused flue can look like a leak, too.

Brickwork, repointing and flaunching are part of our chimney repair work and we often do both in one visit so the scaffold only goes up once.

What affects the cost

The size and position of the stack (at the ridge, mid-slope or against a gable), how many sides need new lead, whether the back gutter base has rotted, the roof covering and access all shape the price. Scaffolding is usually needed to work safely around a stack. You get a free inspection with photos and a written quote.

The repair we're most often called to redo

Chimney leadwork is the job we're most often called in to put right after someone else. Usually the lead is the wrong code, cut too long or buried in sealant. We rebuild the whole detail rather than patching one side, so the leak doesn't come back.