Chimney Repointing in Horsham

Repointing a chimney stack costs £300–£700 depending on height, access and the number of faces, with flaunching renewal £200–£400, cowls £80–£250 per pot, a full lead flashing set £400–£900, 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, so you can see exactly what the stack needs rather than paying for a vague ‘chimney repair’.

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 a cement mortar. Using hard cement on soft historic brick is a common and damaging mistake: it traps moisture and spalls the brick faces over a few winters, causing far more harm than the original worn pointing. We match the mortar to the era, and the joint finish to the original. See pointing in our glossary.

Flaunching is the sloping bed of mortar on top of the chimney stack that seats the pots and sheds rainwater away from them. It’s one of the most exposed pieces of mortar on the whole building, and cracked or missing flaunching is a very common cause of chimney leaks — water gets past the pots and runs down inside the stack and flue. We renew flaunching as part of repointing work, using the correct mortar for the stack’s age, so the top of the chimney sheds water properly again. It’s often the real cause when damp appears on a chimney breast.

A cowl helps in specific situations: where you get downdraught blowing smoke back into the room, where birds nest in an open pot, or where you want to cap an unused flue while keeping it ventilated to prevent damp. Not every chimney needs one, and fitting the wrong type can cause problems, so we advise on whether you’d benefit and which cowl suits during the survey. Capping an unused flue is particularly worth doing properly — sealing it completely without ventilation traps moisture and causes damp, which is why a ventilated cap is usually the right answer.

We access the stack from scaffold or a secured roof ladder depending on the pitch and position, inspect all four faces plus the flaunching and flashings, and photograph the condition so you can see what needs doing before we start. Chimney work is inherently high and exposed, so safe access is the first consideration — it’s not work to attempt off a ladder propped against the stack. Proper access also lets us do the job thoroughly: repoint every face, renew the flaunching, and check the flashings in one visit rather than missing the side you can’t easily reach.

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 itself — a chimney repointed in hard grey cement stands out and damages the brick. Our heritage roofing page covers conservation stacks in detail.

If the mortar has failed but the brickwork itself is sound, repointing is enough and far cheaper. Where the bricks are cracked, spalled or frost-damaged, or the stack has started to lean, a partial rebuild is the safer investment — repointing a structurally failing stack just delays the inevitable. We give an honest assessment at survey based on the actual condition of the brick, not just the mortar. A leaning or badly spalled stack is also a safety issue, since falling masonry is a real risk, so it’s not something to leave once it’s reached that point.

Repointing in the correct mortar lasts decades — lime on period stacks and cement on post-war stacks both give long service when the joints are raked out to a proper depth and finished correctly. The failures that lead to early re-repointing are almost always down to the wrong mortar (hard cement on soft brick) or shallow, cosmetic pointing that doesn’t key into the joint. Done properly, on a sound stack, repointing is a long-term fix rather than 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.

Yes — we can cap an unused flue while keeping it ventilated to prevent damp, or advise on removing a redundant stack where it’s failing and no longer serves any purpose. Capping is usually the better option: it stops rain entering the flue while ventilation prevents the trapped-moisture damp that fully sealing a flue causes. Removing a stack is more involved — it affects the roofline and needs making good — but can make sense where a stack is beyond economic repair. We’ll set out the options honestly rather than pushing the bigger job.

Yes — we match the mortar colour and the joint finish to the existing stack so the repointing blends in rather than standing out, which matters especially on period and conservation properties where a mismatched repair looks worse than the original worn pointing. On older Horsham stacks that means lime mortar tinted and finished to match the weathered original; on post-war stacks, matching the cement colour and profile. Getting the match right is part of doing the job properly — a well-repointed stack should look like it was always that way, not like it’s been patched.