Chimney stack rebuilds and repointing across Devon
A chimney stack takes more punishment than almost any other part of the roof. It stands proud of the roofline, exposed to wind, rain and salt air on every side, and the mortar joints and brickwork gradually wear down as a result. Eventually the pointing erodes, bricks or stone start to spall, and the stack can lean or crack.
This page covers the structural end of chimney work: repointing, partial and full rebuilds, flaunching, pots, and removal of stacks that are no longer needed. For flashing, leaks around the base of the chimney, and other general chimney maintenance, see our chimney repairs page.
Chimney stack repointing
Mortar joints are designed to wear before the brick or stone does, which means repointing is a normal part of chimney maintenance rather than a sign of a bigger problem. Over time, rain gets into hairline cracks in the mortar, and winter frost expands that moisture and pushes the joint apart. On exposed stacks this can happen faster than on sheltered parts of the roof.
Signs that a stack needs repointing include:
- Mortar that has crumbled, is soft, or has fallen away in places
- Gaps between bricks or stones that you can see daylight through
- Damp patches on chimney breasts inside the house
- Loose or rocking pots sitting on worn flaunching
We rake out the old mortar to a sound depth and repoint with a mix that matches the age and exposure of the stack, rather than a hard modern mortar that can trap moisture in older brick or stone. Repointing is usually the proportionate fix where the stack itself is still structurally sound, and it is far cheaper than waiting until the problem becomes a rebuild.
Partial and full chimney stack rebuilds
Sometimes repointing isn’t enough. If the stack is leaning, if bricks are spalling (the face breaking away, often from frost getting behind old render or poor-quality brick), or if there is a visible crack running through several courses, the stack needs rebuilding rather than just repointing.
A partial rebuild takes the stack down to sound brickwork, usually below the roofline or just above it, and rebuilds from there using matching materials where possible. A full rebuild takes the stack down further, sometimes to the roof or below, where the damage is more extensive or long-standing.
We’ll always look at whether a partial rebuild will do the job before recommending a full one. Rebuilding more of the stack than necessary adds cost without adding benefit, and we’d rather set out clearly what’s needed and why.
Things that typically push a stack from “repointing job” to “rebuild job”:
- A visible lean, even a slight one, checked against a plumb line
- Cracking that runs through multiple courses of brick or stone
- Spalling brick or stone faces, particularly on the weather side
- Movement where the stack meets the roofline
- A stack that has already had render applied to hide earlier problems
Flaunching and chimney pots
Flaunching is the mortar fillet at the top of the stack that holds the pots in place and sheds water away from the brickwork. It’s a small detail but an important one, since cracked or missing flaunching lets water track straight down inside the stack.
As part of a rebuild, or sometimes as a standalone job, we renew the flaunching and check the pots for cracks, loose fittings or damage from wind. Pots are usually reused if they’re in good condition, since matching old pots can be difficult, but we’ll replace any that are cracked or unstable.
Removing redundant chimney stacks
Not every stack is still needed. Where a fireplace has been blocked up or a heating system changed, some homeowners choose to remove the stack rather than keep maintaining it. This can be done down to roof level, with the roof made good underneath, or the stack can be removed entirely depending on the property.
This is worth thinking through carefully before work starts. Removing a stack, or even altering it significantly, may require building regulations approval, and if the property is listed or in a conservation area, listed building consent may also be needed. We’d always advise checking this with your local authority before committing to removal, and we’re happy to talk through what the work would involve so you know what to ask about.
Scaffolding and access
Chimney stacks sit at height, often at the highest point of the roof, so safe access matters. Where a job needs it, scaffolding is arranged as part of the work rather than left for the homeowner to organise separately. This also means the access can be used to check surrounding brickwork, flashing and roof coverings while it’s up, which is worth doing on an older roof in any case.
If a wider roof survey makes sense alongside chimney work, our roof surveys service can cover the whole roof rather than just the stack.
Coastal and exposed stacks
Stacks in coastal towns face a harder environment than those inland. Salt-laden wind in Torquay and Plymouth accelerates mortar erosion and brick spalling compared with more sheltered inland properties. Exposed hilltop and rural properties around Exeter see similar wear from wind-driven rain, even without the salt air.
If you’re in Paignton or Newton Abbot and notice mortar loss or a stack that looks slightly off true, it’s worth having it looked at before the next round of winter weather rather than after. We cover chimney stack work as part of our wider roofing service across the areas we cover in Devon, including dedicated roof repairs in Plymouth and roof repairs in Torquay.
A damaged or leaning stack doesn’t just affect the chimney itself. Water getting in around the base can lead to the kind of problems covered in our guide on the most common causes of chimney roof leaks, and flashing issues around the stack are covered in our roof flashing problems guide. After a storm, it’s worth checking the chimney along with the rest of the roof using our notes on what to check after storm damage.
Arrange a chimney stack inspection
If your chimney stack has worn mortar, a visible lean, or cracked or spalling brickwork, get in touch and we’ll take a look and set out what’s actually needed, whether that’s repointing, a partial rebuild or a full one. Call the office on 01392 308173 or the mobile on 07598 001 200, or fill in our contact form and we’ll get back to you.
Frequently Asked Questions
How do I know if my chimney needs repointing or a full rebuild?
Repointing is usually enough if the brick or stone itself is sound and the problem is limited to worn or missing mortar. If the stack is leaning, cracked through several courses, or the brick faces are breaking away, it needs a partial or full rebuild rather than just repointing.
Do you need scaffolding for chimney stack work?
Most chimney stack repairs and rebuilds need scaffolding or another safe form of access, since the stack is usually at the highest point of the roof. Where it’s needed, this is arranged as part of the job.
Can I remove a chimney stack I no longer use?
You can, but removing or significantly altering a stack may need building regulations approval, and listed building consent as well if the property is listed or in a conservation area. It’s worth checking with your local authority before the work starts, and we can talk you through what’s involved.
Will you reuse my existing chimney pots?
Where pots are in good condition we’ll usually reuse them, since matching old pots exactly can be difficult. Any that are cracked, chipped or unstable on their flaunching are replaced as part of the work.
Are coastal chimney stacks more likely to need repair?
Yes. Salt-laden wind and driving rain in towns like Torquay and Plymouth wear mortar and brick faster than in more sheltered inland locations, so stacks in these areas often need attention sooner than you might expect.
