A chimney stack takes more weather than almost any other part of the roof. It’s fully exposed on all sides, often above the roofline. Because of that, the mortar joints between the bricks are usually the first thing to fail. Repointing is the standard fix. Catching it early is far cheaper than waiting for water to reach the stack.
Signs a chimney needs repointing
- Crumbling or missing mortar between the bricks, especially on the side that takes the prevailing weather.
- Damp patches on a chimney breast inside the house, particularly after heavy rain — a classic sign water is getting into the brickwork through failed joints.
- Visible daylight or gaps in the pointing when viewed from the loft, where the stack passes through the roof.
- Loose bricks or a stack that looks like it’s leaning, which needs a structural assessment rather than just repointing — see below.
What the job involves
Repointing means raking out the old, failed mortar to a consistent depth, then re-filling the joints with fresh mortar matched to the property. On a modern chimney, that’s usually a cement-based mix. On a period property, lime mortar is often the right choice instead, since it flexes with the brickwork rather than trapping moisture in it. That’s why lime repointing tends to cost more.
What it costs
According to Checkatrade’s 2026 chimney repointing guide and MyBuilder’s 2026 price guide, UK repointing costs typically range from about £400 to £1,200, averaging around £750:
- A bungalow with easy access starts from around £400.
- A two-storey house needing scaffolding typically runs £600–£900.
- Lime mortar repointing on a period property, which costs and takes longer to apply, is usually £700–£1,200.
Access is often the biggest single factor. Scaffolding can add £250–£300 per day, while a ladder-access job, where it’s safely possible, can save several hundred pounds. Because labour rates and demand are higher there, London and the South East tend to run 10–20% above the national average. Northamptonshire prices are generally closer to the lower half of the ranges above.
When it’s more than repointing
If the stack itself is leaning, has loose or spalling bricks, or the flashing around its base has failed too, that’s a bigger job than repointing alone, often a partial rebuild plus new lead flashing. Because a chimney with failed flashing is also a common source of roof leaks that seem to come from nowhere, it’s worth having both checked at the same survey. Our roof repairs service covers exactly this kind of combined fault.
If a storm has damaged the stack rather than it simply wearing out, our storm damage and insurance guide covers what your insurer will expect to see.
Getting it right
Chimney work is height-critical, and easy to get wrong with the wrong mortar mix. Since a bad repoint can cost more to undo than to do properly, it’s worth asking any roofer the right questions before you hire them. We survey the stack from the loft as well as the roof. We’ll tell you honestly whether repointing is enough, and give you a clear written quote either way, for homes across Kettering and the surrounding villages.
Book a free chimney survey. Because we send photos with every survey, you’ll know exactly what your stack needs before any work starts.