Chimney repairs: UK costs and options in 2026
A chimney stack is the most exposed masonry on the building — wind-driven rain on every face, no shelter, and frost cycling through wet brick all winter. That is why stacks fail long before the walls below them, and why chimney repointing, re-flaunching and eventually rebuilding are among the most common jobs a roofer prices. This guide sets out what each option costs in 2026 and how to tell which one you actually need.
- Repointing: around £600–£1,600
- Rebuild above roof level: around £1,500–£3,500
- Removal: around £900–£2,000 above the roof line
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The parts of a chimney, and what fails
Knowing the vocabulary makes quotes far easier to compare, because roofers price these elements separately:
- Pot and flaunching. The pot sits in a sloped mortar bed called the flaunching. Flaunching cracks with frost and lets water straight into the stack — a very common and relatively cheap fault.
- Stack brickwork and pointing. Exposed mortar erodes; once joints are recessed, the brick soaks up water and frost does the rest.
- Flashing and soakers. The lead that seals the stack to the roof. Old mortar fillets in place of proper lead are a frequent cause of damp indoors.
- Flue and liner. Unlined or failed flues let combustion gases and moisture into the masonry; any appliance being installed or reconnected needs a suitable liner.
- Damp-proof course and trays. Older stacks often have none, so water tracks down inside the brickwork to the ceiling below.
Most “chimney leaks” are flashing leaks
Damp on a chimney breast is more often failed lead flashing or a cracked mortar fillet than a problem with the stack itself. Before agreeing to a rebuild, ask specifically what has been ruled out — a flashing renewal at a few hundred pounds sometimes solves what was quoted as a thousands-of-pounds job.
Chimney repair costs in 2026
Supplied-and-fitted ranges for a typical two-storey house. Access dominates these prices: a stack in the middle of a roof needs more scaffolding than one at a gable end, and scaffolding alone commonly adds £800–£2,500. Add roughly 15–25% for London and the South East.
| Work | Typical 2026 cost | Time on site |
|---|---|---|
| Re-flaunching (new mortar bed to the pot) | £350 – £800 | 1 day |
| Replace a cracked or missing pot | £300 – £700 | 1 day |
| Fit a cowl or capping to a disused flue | £150 – £400 | Half a day |
| Repointing the stack | £600 – £1,600 | 1 – 2 days |
| Renew lead flashing around the stack | £400 – £1,100 | 1 day |
| Rebuild the stack above roof level | £1,500 – £3,500 | 2 – 4 days |
| Rebuild including below-roof brickwork | £3,000 – £6,500 | 4 – 8 days |
| Remove stack above roof and make good | £900 – £2,000 | 1 – 3 days |
| Full removal including breast, with support works | £2,500 – £6,000 | 1 – 2 weeks |
| Flexible flue liner installed | £900 – £2,000 | 1 day |
How to tell which job you need
| What you can see | Likely fix |
|---|---|
| Cracked mortar around the base of the pot | Re-flaunching |
| Recessed, crumbling joints; mortar falling into the gutter | Repointing |
| Damp patch on the chimney breast in the top room | Flashing renewal, or a damp tray |
| Stack leaning, or brick faces spalling off widely | Rebuild above roof level |
| White salt staining inside on the breast | Flue-related damp; liner or capping |
| Unused stack in poor condition on a house with no fires | Removal, or reduce and cap |
Should you remove the chimney instead?
If nothing is connected to the flue and the stack is failing, removing it can be cheaper than rebuilding and it deletes a maintenance liability permanently. Weigh a few things first. Character matters on period properties, and buyers and valuers do notice a missing stack on a Victorian terrace. Removal below roof level is structural work — the breast above has to be supported with gallows brackets or a beam — and that brings Building Regulations into play. On a semi or terrace the stack is often shared with next door, which means agreement with your neighbour and, in many cases, a Party Wall notice.
A middle option is worth knowing: reduce the stack to just above roof level, cap it with a ventilated cover and re-flash. You keep some of the roofline, remove most of the exposed masonry, and pay a fraction of a full rebuild.
Ventilation matters more than people expect
Sealing a disused flue completely at both ends is the classic mistake. Trapped moisture has nowhere to go, condenses inside the masonry and produces damp and salt staining on the chimney breast. Any capping should be ventilated, and an air brick or vent left at the fireplace end, so the flue can breathe gently from top to bottom.
Who should do the work
Chimney work spans two trades. Masonry, flashing and stack rebuilding sit with a roofer or builder — look for NFRC membership, CompetentRoofer registration and TrustMark. Anything involving a working appliance or the flue itself belongs with a specialist: HETAS registration for solid fuel appliances and flue installation, and a NACS (National Association of Chimney Sweeps) member for sweeping and flue inspection. If a stove is being installed or reconnected, the flue work must be certified — you will want that paperwork when you sell.
Chimney work is also a favourite of doorstep traders, because the customer cannot see the roof and cannot check what was done. Never engage anyone who called unannounced. Ask for photographs before and after — every competent roofer takes them as a matter of course — and get three quotes.
Timing and prevention
- Do it while a scaffold is up. If the roof is being repaired or re-roofed, chimney work at the same time saves the whole access cost.
- Repoint before the brick faces go. Once frost has spalled the brickwork, repointing is no longer enough and you are into a rebuild.
- Fit a ventilated cowl on a disused flue to keep rain out while letting it breathe.
- Sweep a working flue annually, or twice a year on wood, using a NACS member.
- Check after storms. Fallen pots and displaced flashing are common storm damage and may be covered by buildings insurance.
FAQs: chimney repairs in the UK
How much does chimney repointing cost in the UK?
Repointing a stack typically costs 600 to 1,600 pounds in 2026, largely depending on stack size and access. Scaffolding is the biggest variable and can add 800 to 2,500 pounds if it is not already up for other work.
Why is my chimney breast damp?
Usually failed lead flashing or a cracked mortar fillet where the stack meets the roof, or cracked flaunching around the pot. A completely sealed disused flue is another common cause, because trapped moisture condenses inside the masonry.
Is it cheaper to remove a chimney than repair it?
Often yes if the flue is unused. Removing a stack above roof level costs around 900 to 2,000 pounds against 1,500 to 3,500 pounds to rebuild it. Removing the breast below is structural work needing support and Building Regulations approval, and on a semi or terrace it may need a Party Wall notice.
Do I need building regulations approval for chimney work?
Repointing, re-flaunching and flashing renewal do not. Removing chimney breasts, altering the structure or installing a flue liner or appliance do, and appliance and flue work should be carried out by a HETAS registered installer who can certify it.
How often should a chimney be swept?
At least once a year for a working flue, and twice a year for wood burning. Use a member of the National Association of Chimney Sweeps, who will also flag flue defects worth acting on early.
Get your chimney assessed and priced
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