Cornwall · England
Chimney stack repairs in Cornwall
Homes in Cornwall are mostly granite and slate-stone cottages. That matters for chimney stack repairs: footings, wall construction and mortar all vary with the age of the building. Most of Cornwall is on firmer ground than the clay belts of the south-east.
Guide price from£515per stack inc VAT
- Area
- Cornwall
- Pricing region
- South West
- Ground
- Mostly firmer ground
- Towns listed
- 9
Is Cornwall prone to ground movement?
Cornwall is mostly granite and slate with little shrinkable clay, so clay subsidence is less common than in the south-east. Historic tin and copper mining has left shafts and workings in places such as Camborne and Redruth, and mining searches are routine there.
Old metal-mine shafts and workings are recorded in places, so mining searches are routine for some properties. Housing stock in Cornwall: Granite and slate-stone cottages, cob buildings, Victorian terraces and post-war estates.
Which repair method suits a home in Cornwall?
Repointing and brick repairs
Eroded joints are raked out and repointed in a mortar suited to the brick, often a lime-based mix on older stacks. Spalled or cracked bricks are cut out and replaced with matched reclaimed or new bricks. On many stacks this, with new flaunching, is all that is needed.
Best for: Upright stacks with weathered joints and some damaged bricks
Flaunching and pot resetting
Old cracked flaunching is broken out, pots are lifted and reset or replaced, and new flaunching is formed to a fall so water runs off. Unused flues can be capped with ventilated caps, which keeps rain out while letting the flue breathe.
Best for: Loose pots and cracked mortar at the top of the stack
Partial or full rebuild
Where the lean is pronounced or the brickwork is badly decayed, the stack is taken down to sound masonry, often to roof level, and rebuilt plumb with new flashings and flaunching. Original bricks are cleaned and reused where possible to keep the appearance.
Best for: Badly leaning or decayed stacks
What happens when we carry out chimney stack repairs in Cornwall?
Look from the ground
Photos from the street and garden, ideally with a zoom, show us the lean, the pots, the flaunching and the state of the pointing. Damp patches inside are worth photographing too, as they help trace the route water is taking.
Check what is below
We ask whether any chimney breasts have been removed, and check the loft and rooms below for cracking. If a breast has gone without proper support, we recommend an independent chartered structural engineer before any stack work.
Repair, restrain or rebuild
The agreed work is carried out: repointing, new flaunching and pots, restraint, or taking the stack down and rebuilding it. Lead flashings where the stack meets the roof are checked and renewed if needed.
Signs you may need chimney stack repairs
- Cracked or missing flaunching around the top of the stack
- Mortar washed out of joints, leaving bricks standing proud
- Chimney pots that are loose, tilted or cracked at the base
- Damp patches on the chimney breast inside, especially after rain
How much will chimney stack repairs cost in Cornwall?
These are guide prices for Cornwall, using South West rates and including VAT. Your written quote follows photos or a survey, and is fixed once the repair is specified.
| Item | Guide price | Per |
|---|---|---|
| Repointing, flaunching and minor brick repairs | £515 – £2,050 | per stack |
| Partial or full stack rebuild | £3,100 – £10,300 | per stack |
| Stack restraint or strappingest. | £410 – £1,250 | per stack |
Do you need approval for chimney stack repairs in England?
In England, underpinning and other work that alters or strengthens a wall or foundation is building work under the Building Regulations (Part A, structure), so building control approves and inspects it. Like-for-like repairs often are not, and we tell you which applies before a price is agreed. Work to a party wall, or excavation close to a neighbour’s foundations, can also need a notice under the Party Wall etc. Act 1996.
Find chimney stack repairs in your Cornwall town
Chimney stack repairs in Cornwall: questions and answers
Why do houses in Cornwall crack?
Cornwall is mostly granite and slate with little shrinkable clay, so clay subsidence is less common than in the south-east. Historic tin and copper mining has left shafts and workings in places such as Camborne and Redruth, and mining searches are routine there. Old metal-mine shafts and workings are recorded in places, so mining searches are routine for some properties. Only an investigation on site can say why a particular building has moved.
How much will chimney stack repairs cost in Cornwall?
On South West rates, chimney stack repairs starts from about £515 per stack, including VAT. The written price depends on the extent of the damage, access and whether an engineer or building control is needed.
Why is my chimney stack leaning?
Most leaning stacks are caused by sulphate attack, where chemicals from old flue gases make the mortar expand more on the wetter side, so the stack bends away from the weather. Frost damage and failed pointing can make it worse. A recently leaning stack can also signal problems below.
Is a leaning chimney dangerous?
A leaning chimney can become dangerous, because stacks are heavy and stand high above the roof. A slight, long-standing lean may be stable for now, but a lean that is worsening, or loose bricks and pots, should be looked at quickly. Keep people away from below if anything looks loose.
Can a leaning stack be straightened?
Not by pushing it back, because the brickwork would crack. A slight lean on a sound stack can be restrained so it moves no further. A pronounced lean is fixed by taking the stack down to sound masonry and rebuilding it plumb.