Chimney Repairs Horsham

Repointing a chimney stack costs £300–£700 depending on height, access and number of faces; flaunching renewal £200–£400; a full lead flashing set £400–£900; cowls £80–£250 per pot; and partial stack rebuilds £600–£1,500. Access is the main variable — a stack reachable from a roof ladder costs less than one needing scaffold. Because a chimney is a system, we assess pointing, flaunching, pots and flashings together and itemise each. Our dedicated chimney repointing page covers the mortar and process in detail.

Yes — conservation-area and listed stacks are repointed in matching lime mortar with a joint finish that matches the original, keeping the work sympathetic and compliant. On a listed building, work affecting the chimney can require listed building consent, and we advise on what’s needed and liaise with Horsham District Council before starting controlled work. Getting the mortar and finish right on a historic stack matters as much as on the roof — a chimney repointed in hard grey cement stands out and damages soft historic brick. Our heritage roofing page covers conservation stacks.

The classic sign is a damp patch on the chimney breast inside — in a bedroom or loft — that worsens after rain, caused by water getting past failed lead or a cracked mortar fillet at the base of the stack. Externally you may see the lead lifted, split, or replaced with a mortar fillet that has cracked. Old mortar fillets are a common bodge that always cracks; proper stepped lead flashing with soakers seals the junction permanently. Renewing the flashing usually solves it without touching the masonry. Our leadwork page covers how proper flashing is formed.

Yes — we can remove a redundant stack that’s failing and no longer serves any purpose, making good the roof where it stood. It’s more involved than repair: the stack is taken down safely, the roof structure closed up, and the covering matched and re-laid over the opening. Where a stack is beyond economic repair or you’ve removed the fireplaces below, removal can make sense — but capping and retaining it is often cheaper and simpler if the stack is sound. We’ll set out the options honestly rather than pushing the bigger job, since removal isn’t always the right call.

It depends on the age of the stack. Pre-1930 stacks — the Victorian terraces near the town centre and Denne Road, and older village properties — need a natural hydraulic lime mortar (typically NHL 3.5) that flexes and breathes with the soft historic brick. Post-war stacks take cement mortar. Using hard cement on soft historic brick is a common, damaging mistake: it traps moisture and spalls the brick faces over a few winters. We match the mortar to the era and the joint finish to the original. See pointing in our glossary and our chimney repointing page.

Warning signs include a damp patch on the chimney breast that worsens after rain, crumbling or missing mortar visible in the joints, cracked or missing flaunching on top of the stack, loose or leaning pots, and staining or vegetation growing on the brickwork. From the ground you can often see cracked pointing, a leaning stack, or lifted flashing at the base. Because the chimney is the most exposed masonry on the building, small faults escalate quickly. If you can see any of these, it’s worth a survey before water tracks down inside the flue and stack.

Repointing in the correct mortar lasts decades — lime on period stacks, cement on post-war stacks — when the joints are raked out to a proper depth and finished correctly. What causes early failure is the wrong mortar (hard cement on soft historic brick) or shallow, cosmetic pointing that doesn’t key into the joint. Done properly on a sound stack, repointing is a long-term fix, not a recurring job. That’s why we rake out to depth and match the mortar to the brick rather than smearing new mortar over the old. Our chimney repointing page explains the method.