A leaning or badly cracked chimney stack in Barnham Broom needs professional attention - but knowing what to do while you wait, and what to leave well alone, can protect your home and keep the job straightforward.
A chimney stack sits fully exposed above the roofline. Rain, frost, wind and UV work on it from every side, every season. Over years the mortar joints open, bricks begin to spall and the flaunching - the sloped mortar collar that holds the chimney pots - cracks and lifts. Water enters the top of the stack, migrates down through the brickwork and eventually shows up as a damp patch on a chimney breast or a musty smell near an unused fireplace.
Repointing slows this process when the brickwork is still fundamentally sound. But when bricks have lost their faces, when the stack is visibly off-plumb, or when the interior courses have been saturated long enough to soften, repointing is not enough. At that stage the damaged section needs to come down and be rebuilt properly.
We rebuild chimney stacks in Barnham Broom and across mid-Norfolk. Depending on the condition of the stack, we may rebuild from the flaunching down, from the roofline upwards, or take the full stack down to ground level if the damage extends that far. Each job is assessed on what is actually there, not on what is easiest or cheapest to specify.
Safe chimney work at height requires proper access - either a scaffold platform or a well-secured scaffold tower. Work carried out from a ladder alone at chimney height is dangerous and produces poor results. Any competent roofer will include access in their quote.
Once on the stack, we take down the deteriorated courses carefully, checking each course as we go until we reach sound, stable brickwork to build from. New bricks are matched as closely as possible to the existing stack. On older properties this can mean sourcing hand-made or second-hand brick, or working with flint if the original stack used it. We bed the new brickwork in a mortar mix appropriate to the age of the property - older stacks built with lime mortar need a soft lime-based mix, not a hard cement mix which would cause the surrounding bricks to spall.
New flaunching is formed at the top to bed the pots securely and shed water away from the stack. The lead step and back-gutter flashing where the stack meets the roof is replaced or fully reset as part of the job. Failed flashing is one of the most common routes for water into a roof structure, and ignoring it during a chimney rebuild is a false economy.
Typical cost for a chimney rebuild from the roofline in the Dereham and mid-Norfolk area runs from approximately £1,500 to £3,500. Stack height, the extent of the damage, access requirements and material matching all affect the final figure. A full rebuild from ground level will cost more.
These are the things worth checking from the ground or from an upstairs window:
Any of these warrants getting a roofer onto the stack to assess the condition properly. A visual check from the ground gives you a starting point, but the real picture only becomes clear once someone is up there with a full view of the top courses and the flashing.
If you have spotted a problem and have arranged for a roofer to attend, there are practical steps you can take in the meantime to limit damage and keep your household safe.
If the chimney is no longer in use and you suspect the stack is letting water in, keep the fireplace closed off and place a bucket or absorbent material below any damp patch on the chimney breast. Damp that has been sitting in a wall for a long time can continue to work its way down even after rain stops, so this is worth monitoring over several days, not just immediately after a wet spell.
If you have a functioning fireplace and use it regularly, continue to do so if the flue is drawing correctly and there is no smell of smoke in the room. Keeping the flue warm and dry is actually beneficial. If the draw has reduced significantly or you notice smoke entering the room, stop using it and have the flue inspected before lighting further fires.
If the stack is visibly leaning and you are concerned about the structural risk, keep people away from the area directly below the chimney on the roof slope and, where possible, the ground below the eaves on that side of the house. A leaning stack is an unstable stack. Contact a roofer as a priority rather than waiting for a convenient appointment slot.
Keep a note of when you first noticed each symptom and whether it has changed. This information is useful to the roofer assessing the job and helps them understand how quickly the deterioration is progressing.
This is important. There are DIY fixes that appear to solve a chimney problem but make it significantly worse, or create new ones.
Do not apply a film-forming sealant, exterior masonry paint or a non-breathable waterproofer to the chimney stack. These products trap moisture inside the brickwork. The stack will appear sound from the outside but the internal faces of the bricks continue to deteriorate. When that moisture freezes, the damage is severe and tends to be worse than if no product had been applied at all.
Do not attempt to repoint the chimney stack from a domestic ladder propped against the stack itself. Chimney stacks are not stable platforms and a ladder propped against them at that height creates a serious fall risk. If you want to apply a breathable waterproofer yourself after the work is complete, do so only if you can reach the stack safely from a properly secured scaffold tower, or have the roofer apply it as part of the job.
Do not use expanding foam or silicone sealant to fill cracks in the flaunching or around the pots. These materials are not suitable for external masonry exposed to thermal movement and weather. They may hold for a season, then crack open again, and can make a proper repair harder to execute cleanly.
Do not attempt to remove a chimney pot yourself. Pots are heavier than they look and at that height the consequences of one falling are serious. If a pot is loose, that is a job for someone working from a proper platform.
A properly rebuilt chimney will perform well for many years without significant intervention, but a small amount of periodic attention keeps it that way. Once the mortar has cured - allow four to six weeks - a breathable silane or siloxane-based waterproofer applied to the external brickwork helps repel rain without trapping moisture vapour. This is a worthwhile step, particularly on north-facing or particularly exposed stacks.
Check the flaunching visually every year or two. Fine shrinkage cracks are normal and can be left, but cracks that open to a visible gap or allow water to sit should be repaired promptly. Repointing a small section costs far less than another rebuild further down the line.
We work on chimney rebuilds in Barnham Broom and across the Dereham area, including nearby villages and the broader mid-Norfolk region. If your stack is giving you concern, call us to arrange an assessment so we can tell you exactly what condition it is in and what needs doing.
No obligation · We usually respond within 2 hours
Storm damage, active leak, damaged ridge - we aim to be on-site within 24 hours.
