Chimney repair costs at a glance (UK, 2026)
| Repair type | Typical UK cost (inc. scaffold) |
|---|---|
| Chimney repointing (standard stack) | £400–£1,200 (avg £750) |
| Chimney repointing with lime mortar (period property) | £700–£1,500 |
| Flaunching repair (mortar around chimney pot) | £200–£500 |
| Replace chimney pot | £150–£400 per pot |
| Partial chimney rebuild (above roofline, 50%) | £600–£2,000 |
| Full chimney stack rebuild above roofline | £1,000–£3,500 |
| Scaffolding (if not included above) | £500–£1,200 |
Scaffolding is nearly always required for chimney work. Most contractors include it in their quote. If a quote seems very low, check whether scaffold is included — it is not a job you can do safely from a roof ladder.
Chimney repointing
Repointing is the most common chimney repair. The mortar between the bricks of a chimney stack weathers faster than any other part of a house because it is fully exposed, catches rain on all four sides, and is subject to repeated freeze-thaw cycles in winter.
Most chimney stacks need repointing every 15–25 years, depending on their exposure. South-facing and exposed chimney stacks deteriorate fastest.
The average cost to repoint a standard two-pot chimney stack in the UK is around £750 including scaffolding. The range is £400–£1,200. Period properties (pre-1920) need lime mortar rather than cement — this adds cost but is essential to prevent damage to the original bricks. See our guide to pointing and repointing for more on mortar types.
Flaunching repair
Flaunching is the mortar bed around the base of the chimney pot that holds it in place and seals the top of the stack. It is exposed to the elements and commonly cracks or breaks away over time. Cracked flaunching allows water into the chimney, causing damp internally.
Repairing or replacing flaunching costs £200–£500. It is often done at the same time as repointing to save on scaffold costs.
Chimney rebuild
If a chimney stack is structurally damaged, leaning, or the bricks have severely deteriorated, repointing is not enough — the stack needs to be rebuilt. The extent of the rebuild depends on the damage:
- Partial rebuild: top section of the stack removed and rebuilt with matching bricks. Costs £600–£2,000 depending on how much is demolished.
- Full rebuild above roofline: entire stack above the roof covering dismantled and rebuilt. Costs £1,000–£3,500. If the chimney breast inside the house is also damaged, costs rise significantly.
- Full chimney removal: if the chimney is not used and causing problems, full removal (breast and stack) typically costs £2,000–£5,000+. Structural works to the ceiling and roof are also required.
What causes chimney damage?
- Weathering and frost: the main cause of mortar deterioration. Water gets into cracks and expands when it freezes, breaking the mortar apart.
- Wrong mortar type: cement mortar on old chimneys traps moisture and causes brick faces to spall. Lime mortar is correct for pre-1920 buildings.
- Sulphate attack: in chimneys that are still in use, sulphates from flue gases can react with cement mortar, causing it to expand and crack. Sulphate-resistant cement or lime mortar is the remedy.
- Tree roots and plant growth: ivy and other plants growing into the chimney stack cause significant structural damage. Remove plant growth before repointing.
- Lightning and storm damage: chimney stacks are vulnerable to wind and lightning. Leaning or displaced stacks require urgent professional assessment.
Can I spot chimney problems from the ground?
From the ground with binoculars, look for:
- Gaps or missing mortar between bricks
- Crumbling or fallen pieces of mortar or brick
- A cracked or missing flaunching at the base of the chimney pot
- Vegetation growing in the stack
- A leaning or displaced chimney pot
- White staining (efflorescence) on the stack — a sign of water ingress
Internally, damp patches on a chimney breast wall — particularly after rain — are a strong sign that the stack needs attention.
Frequently asked questions
- Does a chimney repair need planning permission?
- Routine chimney repairs — repointing, flaunching, pot replacement — do not need planning permission. Rebuilding a chimney stack is also generally permitted development unless the property is listed or in a conservation area where any external works may need consent.
- Can I repoint a chimney myself?
- The repointing itself is achievable for a confident DIYer — but the access is the problem. Working on a chimney stack without proper scaffold is extremely dangerous. Roof ladders and cherry pickers are not substitutes for a proper scaffold. For chimney work, the professional charge is heavily weighted towards the scaffold cost rather than the labour itself, which makes DIY less of a saving than it appears.
- My chimney is not in use — does it still need maintaining?
- Yes. A redundant chimney stack still needs to be kept weathertight. A leaking chimney causes internal damp regardless of whether it is in use. Options include capping the pot (which prevents rain entry but allows ventilation) and maintaining the external repointing. A fully decommissioned chimney should have a ventilated cap fitted to prevent condensation build-up inside.
- How do I know whether to repair or rebuild my chimney?
- If the mortar joints are deteriorated but the bricks are sound, repointing is sufficient. If individual bricks are spalling (faces breaking away) or the stack is leaning, rebuilding is needed. If in doubt, ask two or three experienced bricklayers to look at it and give their honest assessment — and get their opinions in writing.