Chimneys & Leadwork
If a house has a chimney, the chimney is the first suspect for any leak near it. Stacks take the worst of the weather from every direction, and the junction where they pass through the roof is the hardest detail on the whole roof to keep watertight. This section covers chimney and leadwork repairs.
Stacks take the worst weather on the house — kept sound, top to flashing.
Raked out and re-mortared properly — the job that keeps a stack alive.
Stepped, chased and dressed — the fifty-year seal at every junction.
Valleys, aprons, bays and parapets — the wider craft of lead on roofs.
Damp on the chimney breast — five suspects, one methodical diagnosis.
Why chimneys leak
A chimney has more failure points per square metre than any other part of a roof: mortar joints that weather out, flaunching (the mortar cap holding the pots) that cracks and lets water into the stack, and the lead flashings at the base that either fatigue, lift in wind, or were never stepped into the brickwork properly in the first place. Water getting in at any of these shows up indoors as damp on a chimney breast — often a floor or two below the actual fault. Our leaking chimney page walks through the diagnosis.
The work we do on stacks
Repointing — raking out failed joints and re-mortaring — is the bread-and-butter job that keeps a stack sound. Beyond that: re-flaunching, replacing damaged bricks, re-bedding or replacing pots, fitting caps and cowls to keep rain and birds out of open flues, and rebuilding stacks that have moved or spalled beyond patching.
Leadwork is a trade of its own
Lead is the best flashing material there is — it moves with the building and lasts half a century or more — but only when it's cut, dressed and fixed correctly, with proper laps and expansion room. We repair and renew step and cover flashings, lead valleys, aprons and back gutters, and we'll tell you plainly when a previous "repair" in mastic or flashing tape is the reason the leak keeps coming back — those products buy months, not decades.
Related reading: leaking roof repair covers leak-finding across the rest of the roof, and why is my roof leaking? is the place to start if you're not sure the chimney is the culprit.
Chimneys & Leadwork — your questions answered
Damp has appeared on my chimney breast — is that the roof? +
Can you repair flashing without scaffolding? +
Is an unused chimney worth maintaining? +
Not sure what your roof needs?
Send us photos of the damage — our team will assess and recommend, at no cost or obligation.