Chimney Lining Costs UK — What to Charge to Line a Chimney in 2026

What Chimney Lining Is and Why It's Needed

Chimney lining means installing a continuous flue liner inside an existing masonry chimney so it can safely carry combustion gases from an appliance to the outside air. Most jobs are driven by a new wood-burning or multi-fuel stove, but you'll also line chimneys for open fires, gas and oil appliances, or simply to fix a flue that's failed.

Older chimneys are frequently unlined, or the original clay/parge lining has cracked and become porous. A failed flue leaks combustion products — including carbon monoxide and tar — into the building or adjoining flues, and won't draw properly. A modern stove runs hotter and at a lower flue-gas volume than the open fire the chimney was built for, so a correctly sized stainless liner is usually required to make the appliance safe and efficient. Any new or replacement liner is notifiable work under Building Regulations Part J and must be either signed off by a HETAS-registered installer or notified to Building Control.

Quick Reference: Chimney Lining Prices UK 2026

Indicative Pricing — What to Charge

For a standard two-storey house with reasonable roof or scaffold access, a flexible stainless-steel liner supplied and fitted for a stove typically comes in at £600–£1,200. Longer or taller chimneys, harder access, external runs needing a twin-wall insulated system, or premium 904-grade liner push the figure to £1,200–£2,500+.

The cleanest way to build a quote is to price the liner per metre and add the components and labour on top. Flexible 316/904-grade liner runs roughly £25–£60 per metre as material, then you add the pot or cowl, the top clamp, the register/closure plate, backfill or insulation, your labour, and any scaffolding or access. Pricing it this way means you can flex the quote accurately when a chimney turns out to be a metre taller than the survey suggested, or when a customer wants a higher-grade liner.

• Flexible liner material: £25–£60/m (316-grade lower, 904-grade higher)
• Pot / cowl / top clamp: £60–£200
• Register / closure plate with access door: £40–£120
• Insulation backfill (vermiculite or wrap): £60–£200
• Labour (typically a 1–2 person day): £250–£500

Liner Grades and Types

316 vs 904 Grade

Flexible liners come in two main stainless grades. 316-grade (sometimes sold as 316L or Grade 1) is the standard choice for seasoned wood and smokeless fuel on an intermittently used stove, and usually carries a warranty in the region of 10–15 years for that use. 904-grade (Grade 2) is a heavier, more corrosion-resistant stainless used for harsher conditions — house coal, bituminous fuel, heavy or 24/7 burning, and back boilers — and typically comes with a longer warranty. Specifying 316 on a chimney that'll burn coal day and night is a common warranty-voiding mistake.

Flexible vs Rigid, Pumice and Concrete

Flexible stainless liners are the go-to for retrofitting a stove into an existing masonry chimney — they snake down past bends and offsets and are quick to install from the top. Rigid stainless sections are used where a straight, robust flue is wanted or for certain gas/oil appliances. Pumice and concrete liners are usually installed in new-build or full chimney rebuilds rather than retrofits — they offer excellent insulation and longevity but are a heavier, more involved job. For external chimney runs or where a flue has to leave the building, a twin-wall insulated flue system is used instead of lining masonry, which carries a higher material cost and is reflected at the top of the price range.

The Components of a Lining Job

A compliant liner install is more than just the flexible tube. A typical job includes:

• The liner — correct diameter for the appliance, the right grade for the fuel, run continuously top to bottom.
• Top clamp and cowl/pot — the liner is clamped at the top of the chimney and finished with a pot-hanging cowl or anti-downdraught/bird-guard cowl.
• Bottom closure / register plate — a stainless plate sealing the base of the chimney void to the liner, with an access door for sweeping, fitted above the stove or in the builder's opening.
• Insulation backfill — either poured vermiculite (often mixed with cement) into the void around the liner, or a fitted liner wrap, to keep flue-gas temperatures up and improve draw.

Skipping the insulation is the single most common corner cut. An uninsulated liner runs cooler, draws poorly, and tars up far faster — leading to callbacks and a dissatisfied customer. Always price the backfill in.

The Survey, CCTV and Smoke Test

Quote off an inspection, not the customer's description. A proper survey before you commit a price should establish the chimney's height and number of storeys, the internal condition (a CCTV flue camera reveals bends, offsets, soot loading and cracks), and whether an old liner needs removing. Always sweep the chimney first so the camera and the new liner aren't fighting through soot and debris.

After installation, a smoke / integrity test confirms the liner draws correctly and that there are no leaks into the building or adjoining flues. This is part of a professional handover and should be in every quote — bundle the CCTV survey and post-install test into your price rather than treating them as optional extras a competitor will skip.

Building Regs Part J and HETAS Sign-off

Lining or relining a chimney is notifiable work under Building Regulations Approved Document Part J (combustion appliances and fuel storage systems). You have two compliant routes:

• HETAS-registered installer — self-certify the work under the competent person scheme and issue a HETAS certificate, which is registered and a building regulations compliance certificate is sent to the customer. This is the fast, low-friction route most stove installers use.
• Building Control notification — if you're not registered with a competent person scheme, the work must be notified to the local authority Building Control, who will inspect and issue completion. This adds time and a council fee.

Either way the customer needs documentation — they'll be asked for it when they sell the house, and an unregistered installation can hold up a sale. A carbon monoxide alarm is required in the room with the appliance under Part J. Make clear in your quote which route you're using and what certificate the customer will receive.

Cost Drivers — What Pushes the Price Up

Two chimney lining jobs that look identical from the living room can differ by hundreds of pounds. The main drivers are:

• Chimney height / number of storeys: more metres of liner, more labour, and bigger access requirements. A 3-storey townhouse is a very different job to a bungalow.
• Access and scaffold: a steep roof, fragile tiles, or no safe way onto the stack means a tower, scaffold or MEWP — frequently the largest single line on the quote.
• Liner grade and diameter: 904-grade costs noticeably more than 316, and a larger flue diameter uses more material.
• Insulation method: poured vermiculite backfill versus a fitted wrap changes both material and labour.
• Removing an old liner: extracting a corroded or collapsed existing liner adds time and risk before the new one goes in.
• Bends and offsets: a chimney that dog-legs around a flue from another floor is slower and harder to feed a liner through, and may need a more flexible (and pricier) liner.

What's Included — Worked Example

Take a typical job: lining a standard two-storey terraced house for a new 5kW wood-burning stove, single straight flue, tower-access to the stack, around 7 metres of liner.

• Sweep + CCTV survey: £90
• 316-grade flexible liner, 7m @ ~£35/m: £245
• Pot-hanging cowl + top clamp: £120
• Stainless register plate with access door: £80
• Vermiculite backfill insulation: £90
• Access tower hire: £120
• Labour (1.5 days, 2 people part of the time): £400
• HETAS certificate + smoke test: included

That lands around £1,000–£1,100 all-in for the customer, comfortably inside the £600–£1,200 band, with the liner and labour as the biggest elements. Swap the tower for a full scaffold, add a storey, or specify 904-grade and you're quickly into the £1,200–£2,500+ range.

Practical Pitfalls to Avoid

• Wrong liner diameter: match the liner to the appliance's flue outlet and the manufacturer's spec — undersizing chokes the draw, oversizing cools the gases and causes condensation and tarring.
• Skipping insulation: an uninsulated liner runs cold, draws badly and tars up. Always backfill or wrap.
• Not sweeping first: feeding a new liner past soot and old debris damages it and gives a false survey picture. Sweep before you camera and before you line.
• No smoke / integrity test: never hand over without confirming the flue draws and doesn't leak into the building or neighbouring flues.
• Wrong grade for the fuel: 316 on a 24/7 coal-burning flue voids the warranty and corrodes early — spec 904 where the burning is heavy.
• Forgetting the sign-off: the job isn't finished until it's certified — HETAS or Building Control — and the customer has a CO alarm and the paperwork.