Question answered
Replacing a chimney pot
The short answer
A broken chimney pot can be replaced on its own, usually in a day, once there is safe access to the top of the stack. The old pot is lifted off, the flaunching beneath it is renewed, and a matching pot is bedded in mortar so it sheds water. The price depends on scaffold, how many pots there are, and whether the stack below is sound enough to carry them.
A cracked or leaning pot is a small part on a tall stack, but it sheds water and holds the flue open. Replacing it is mostly about access and the bed beneath it.
Why pots crack and lean
A chimney pot is a clay tube, bedded in mortar at the top of the stack. Rain soaks into it, frost expands the water and the clay splits, usually along the top rim or at the join with the bed. Heat from a fire used to dry the pot out; on an unused flue nothing does, so damp lingers.
The bed matters as much as the pot. This is the flaunching, the sloping mortar fillet that holds the pot upright and throws water off the top of the stack. When it cracks, water runs behind the pot and into the brickwork, and the pot starts to tilt as the mortar lets go. A leaning pot is the commonest reason for calling someone out.
Look from the ground with binoculars: chips of clay on the roof or in the gutter, a visible gap round the base, or a tilt against the sky all point to a pot that needs attention.
Access decides how the job is done
A clay pot weighs more than it looks, and it sits at the highest and least stable point of the house. A roofer cannot safely lift one off a ladder. A scaffold or a tower, with a working platform at stack height, is the sensible way to reach it, and on a tall Victorian stack that platform often has to stand on the pitch itself.
MyBuilder's scaffolding guide, updated 21 August 2026, gives a typical UK range of £400 to £900 for chimney scaffolding. On many jobs that is the largest single item, which is why it makes sense to have other chimney repairs done on the same visit rather than coming back.
If the scaffold takes up part of the road or pavement, the scaffold firm has to obtain a highway licence in writing before it goes up. West Sussex County Council asks for 10 working days' notice for that, so the wait belongs in your timetable.
Flaunching: the part that gets overlooked
When the pot comes off, the old flaunching comes off with it, and the top course of brick is checked. Weak or sandy pointing in the top few courses is common, and a new pot bedded on bad mortar will not last. The stack is repointed to the right depth, and old brickwork is better served by a lime-based mix; our page on lime mortar for chimneys explains when that matters.
The new bed is gauged to grip the pot without being harder than the brick around it, and it is trowelled to slope outwards on every side, so rain runs away from the clay and off the stack. A thin smear that just hides a gap is not a flaunching. It lasts a winter.
On a stack with several pots, every bed is checked even if only one pot is broken, because they tend to age together.
Matching the pot to the house
Pots are not all the same. Victorian terraces often have tall round or ornate pots, and later houses have plainer shapes, in buff, red or terracotta clay. A pot that is the wrong height, colour or style stands out against the skyline, and in a conservation area the council may care about the look of the street.
Many pots are still made new, and where an exact match is not available, a reclaimed pot or a close modern equivalent can be used. On a listed building, or in an area with an Article 4 direction that touches chimneys, check with the council first, because what counts as like-for-like is decided by the planning team, not the builder.
It also pays to ask about the pot's height and shape before it comes off. Photographs of the old pot in place, taken from the roof, are the best guide to what the new one should look like. Our chimney repairs page lists the other work that is usually done on the same visit.
Shared stacks, sweeps and what to book
If the stack serves a neighbour's flue as well, the pots on it may belong to both houses. Work on one pot affects the shared bed, and you will need to speak to the neighbour, particularly about scaffold access. See who pays for a shared chimney stack for how that usually works.
A sweep can clear soot and check the flue from inside; a roofer deals with the pot, the bed and the stack. If you are not sure which you need, read chimney sweep or roofer.
We photograph the pot, the bed and the pointing from the top of the stack, and the written quote follows with one total price. Check any quote you compare it with for scaffolding and VAT.
Pots: two more questions
Is a cracked pot dangerous or just untidy?
It can be both. A pot that has split or is loose can drop pieces onto the roof, the garden or a path below, and a tilting one can fall in a gale. A hairline crack in a firm pot is less urgent, but it still lets water in, so have it looked at before winter.
Can I replace just the flaunching and keep the old pot?
Yes, if the pot is sound. The pot is lifted off, the old bed is chipped out, the top course is checked and the pot is re-bedded on fresh mortar with the right fall. Many leaking stacks turn out to need only that, and the pot is reused.
Tell us about your roof
Describe what is happening and we will call you back to arrange a visit.
- Photographs of what we find
- A written quote with one total price
- Or call 01903 299063
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