Chimney Liner Guide: Sizing, Insulation, and Insert Relines
Updated October 2026
If you're installing a wood insert into a masonry fireplace, or relining an old masonry chimney for a freestanding stove, you need a stainless steel flex liner run the full height of the chimney, sized to match your stove's flue collar. The Drolet and Englander wood stoves and inserts we carry use a 6-inch collar, and our stainless steel chimney liner kits come in 4 to 8 inches, in 304 stainless (Vortex) and 316Ti stainless (Forever Flex, rated for wood, oil and gas) — always confirm against your stove's manual before ordering. Below: how sizing works, which steel grade you need, when insulation matters, and what it costs.
Chimney liner cost, in short:
- DIY kit: a complete stainless liner kit runs $399 to about $1,123, from the 4" VOLKA-425 and the 6" VOLKI-625 insert kit ($449) up to long 316Ti Forever Flex kits. Factory pre-insulated kits start at $1,026.99.
- Professionally installed: $1,500 to $4,000, about $2,500 on average (HomeGuide, HomeAdvisor). Masonry repairs, offsets and steep roofs add more.
- Doing a straight flue yourself typically saves $1,000 to $3,000. See the full cost breakdown below.
No Sales Tax in any state, and every liner kit ships free.
What a stainless steel chimney liner does
A liner is a continuous stainless steel flue that runs inside your masonry chimney from the stove or insert connection all the way to the top. It gives the exhaust a correctly sized, sealed, smooth path out of the house. Old masonry chimneys often have cracked clay tiles, gaps, or a flue that's far too large for a modern stove — all of which weaken draft and let creosote build where you can't see it. The liner fixes all three problems at once.
For wood inserts this isn't optional: Drolet and Englander insert manuals call for a full-height liner connection, and most inspectors and sweeps will insist on one. The same applies when you replace an old fireplace stove like a Better 'n Ben's, which in most original installs vented straight into the old masonry flue with no liner. For a freestanding stove venting into an existing masonry chimney, a reline is how you bring that chimney up to the job. (New Class A chimney systems and stovepipe are a different animal — that's covered in our chimney and stovepipe guide.)
Chimney liners for brick chimneys
Most relines go into brick or block chimneys — and "flue liner" and "chimney liner" mean the same thing here. A brick chimney usually already has a clay tile liner inside it, or, in older houses, no liner at all. Three situations call for a stainless liner:
- Cracked, shifted or missing clay tiles. This is what a chimney inspection usually finds. Damaged tile no longer seals the exhaust from the brick, and it cannot contain a chimney fire.
- A flue that is too big for the stove. Clay flues built for open fireplaces are far larger than a 6-inch stove collar. The exhaust slows and cools in the oversized space, draft weakens and creosote builds — see sizing below.
- No liner at all. Older brick chimneys built without tile need a liner before any stove or insert connects to them.
Before you order, measure the inside of the clay tile at the top of the chimney. The liner — plus insulation, if you add it — has to slide down the full height, so the opening needs to be comfortably larger than the liner's outside diameter. Check the minimum flue size in the kit instructions. A tight or offset flue is where a chimney sweep earns their fee.
Which stainless grade: 304, 316 or 904?
You will see liners sold in several stainless grades, and the difference is corrosion resistance rather than strength.
- 304 / 304L — the standard grade for wood-burning appliances. Wood exhaust is comparatively benign, and 304 is what the great majority of wood stove and insert relines use. Our Vortex kits are 304.
- 316 / 316Ti — higher corrosion resistance. Typically specified for coal, oil and some gas appliances, whose exhaust is more aggressive, and occasionally chosen for wood in very wet climates or exposed exterior chimneys. Every Forever Flex kit we sell is 316Ti.
- 904 / AL29-4C — premium alloys aimed at condensing and high-corrosion applications, usually oil and certain gas appliances.
The practical answer: if you are burning wood, 304 is the appropriate and standard specification, and paying for 904 buys corrosion resistance you will not use. If you are burning coal or oil, or converting an appliance that does, you want 316 or better — our Forever Flex 316Ti kits are rated for wood, coal, oil and gas. Don't fit a 304 liner to a coal or oil appliance.
What size chimney liner do I need?
Match the liner diameter to your stove's flue collar. That's the whole rule. The wood stoves and inserts we sell have a 6-inch collar, so a 6-inch liner is the correct match — check the specifications page in your manual to confirm yours. Going larger is not better: an oversized flue lets exhaust slow down and cool, which hurts draft and accelerates creosote. Going smaller restricts the exhaust and is unsafe. Match the collar.
If your appliance needs a 4-inch liner — the Drolet ECO-65R and some smaller appliances do — we stock 4-inch kits in both lengths: the VOLKA-425 ($399) at 25 ft and the VOLKA-435 ($519) at 35 ft, plus the 316Ti Forever Flex 4" tee kit and 4" appliance connector kit in 20 to 35 ft.
5-inch, 5.5-inch, 7-inch and 8-inch liners come in our Forever Flex range: the 5", 5.5" and 7" tee kits, and the 5.5" and 8" appliance connector kits. Do not fit a 6-inch liner to a 5-inch collar to make it work; the mismatch will cost you draft and create a creosote problem. Order the correct diameter, or reach us by email (info@stovesource.com) or text at 1-888-866-8206 and we will tell you honestly whether your appliance is one we can supply.
For length, measure from where the liner connects at the stove or insert up to the top of the chimney, then round up — extra liner can be trimmed, a short liner is a returned liner.
Oval and rectangular liners for narrow clay flues
Some clay-tile flues, especially the narrow rectangular tiles in many older houses, are too small inside for a round liner of the size your appliance needs. Oval and rectangular flexible liners solve that: they are flattened to slide down a tight flue while keeping roughly the flow area of the round size. At the appliance end the liner converts back to round with an oval-to-round adapter, so it still connects to your stove's round collar. Sizing depends on the flue's inside dimensions and your appliance's required flue size, so email info@stovesource.com or text 1-888-866-8206 with both before you order and we will match the liner and fittings.
| Fitting | Oval liner | Rectangle / square liner |
|---|---|---|
| Top plate | Forever Flex oval top plate | Forever Flex rectangle top plate |
| Cap | Forever Flex oval cap | Forever Flex rectangle cap |
| Tee and tee cap | Oval tee and tee cap | Rectangle tee (round take-off) and tee cap |
| Pulling nose cone | Oval nose cone | Rectangle nose cone |
| Connector | Oval connector | Rectangle connector |
| Convert to round | Oval-to-round adapter | Use the rectangle tee's round take-off |
Running a HomeSaver liner? We also carry the Small Ovalflex adaptor, top/bottom plate and storm collar, and the Rectangleflex adaptor, top/bottom plate, top clamp, end cone and storm collar.
What a chimney liner costs
Our stainless steel liner kits, complete with top plate, cap and connector hardware:
| Kit | Size | For | Price |
|---|---|---|---|
| Stainless Flex Liner Kit — VOLKA-425 | 4" × 25 ft | 4-inch appliances, chimneys up to 25 ft | $399 |
| Stainless Flex Liner Kit — VOLKA-435 | 4" × 35 ft | 4-inch appliances, taller chimneys | $519 |
| Vortex Insert Liner Kit — VOLKI-625 | 6" × 25 ft | Wood inserts, chimneys up to 25 ft | $449 |
| Vortex Insert Liner Kit — VOLKI-635 | 6" × 35 ft | Wood inserts, taller chimneys | $559 |
| Stainless Flex Liner Kit — VOLKA-625 | 6" × 25 ft | Freestanding stove relines | $499 |
| Stainless Flex Liner Kit — VOLKA-635 | 6" × 35 ft | Freestanding stove relines, taller chimneys | $579 |
| Forever Flex 4" Tee Kit | 4" × 25–35 ft | Appliance through a thimble; wood, oil or gas | From $621.99 |
| Forever Flex 4" Appliance Connector Kit | 4" × 20–35 ft | Top-connect appliance; wood, oil or gas | From $575.99 |
| Forever Flex 5" Tee Kit | 5" × 20–40 ft | 5-inch appliance through a thimble | From $637.99 |
| Forever Flex 5.5" Tee Kit | 5.5" × 20–35 ft | 5.5-inch appliance through a thimble | From $655.99 |
| Forever Flex 5.5" Appliance Connector Kit | 5.5" × 25–35 ft | 5.5-inch top-connect appliance | From $789.99 |
| Forever Flex 6" Tee Kit | 6" × 15–40 ft | Freestanding stove through a thimble | From $683.99 |
| Forever Flex 6" Appliance Connector Kit | 6" × 15–35 ft | Wood inserts and top-connect stoves | From $633.99 |
| Forever Flex 6" Pre-Insulated Tee Kit | 6" × 20–30 ft | Thimble connection, insulation built in | From $1,192.99 |
| Forever Flex 6" Pre-Insulated Appliance Connector Kit | 6" × 20–30 ft | Inserts, insulation built in | From $1,026.99 |
| Forever Flex 7" Tee Kit | 7" × 30 ft | 7-inch appliance through a thimble | $1,038.99 |
| Forever Flex 8" Appliance Connector Kit | 8" × 25 ft | 8-inch top-connect appliance | $1,083.99 |
The six Vortex kits are 304 stainless. The Forever Flex kits are 316Ti, rated for wood, coal, oil and gas, and come in 15 to 40 ft depending on size. No Sales Tax in any state, and every kit ships free. Browse the full range in chimney liner kits.
What professional relining costs
Buying the kit is one number; having someone fit it is another. HomeGuide's 2026 figures put chimney liner installation at $1,500 to $4,000, with a stainless steel reline specifically at $900 to $3,800. HomeAdvisor puts the average at about $2,500, with most projects landing between $1,500 and $5,000. The spread is real: chimney height, roof access, flue condition and whether the old liner has to come out all move the number.
| Job | Typical cost |
|---|---|
| DIY reline, straight flue, our kit (uninsulated) | $399 – $1,123 |
| Professional stainless reline | $900 – $3,800 |
| Chimney liner installation, all types (average $2,500) | $1,500 – $4,000 |
| Level 1 chimney inspection (often bundled) | $150 – $500 |
| Add: masonry repair found at inspection | $500 – $2,000+ |
| Add: offsets, cathedral ceiling or steep roof | $500 – $1,500 |
That gap is the single largest saving available anywhere in a wood stove project. A straight-shot reline done yourself on a $499 kit typically saves $1,000 to $3,000 against an installed quote — more than the price difference between a budget stove and a mid-range one.
It is also the reason to get the inspection done first. The surprises that blow up a relining budget — a cracked crown, spalled masonry, a flue that turns out never to have been lined — are all things an inspection finds before you have bought anything. Get the installed price in writing, and ask whether a pre-install inspection is included; on an older chimney it should be. Our wood stove installation cost breakdown puts relining in the context of the whole project.
Insert kits versus standard reline kits
The insert kits (VOLKI) are configured for the classic insert install: liner drops down the chimney, connects to the insert's collar at the bottom, and terminates at the top of the masonry chimney. The standard kits (VOLKA) are configured for relining a masonry chimney that a freestanding stove connects into through a thimble.
Forever Flex kits follow the same split. A tee kit is for a stove that enters the chimney through a thimble: the tee sits at the bottom of the liner and its cap gives you a cleanout. An appliance connector kit is for an insert or appliance that connects straight up into the liner. On the 5" and 5.5" tee kits you can also choose an 8" x 8" terracotta top plate for chimneys with clay flue tile.
Two accessories solve the awkward connections at the bottom. The hook-up liner system ($79) makes the liner-to-collar connection on the Drolet Escape 1800-I and the Englander Blue Ridge 150-I, 300-I, and 500-I inserts. If your insert's collar doesn't line up with the chimney flue above it, the offset liner adaptor ($279) — which fits all Drolet and Englander wood inserts — bridges the misalignment. Need an insert sooner? The Carolina Model 21 NC works as a fireplace insert and is in stock: $2,248 with its trim kit, heats 800–1,800 sq ft, made in the USA (Ships in 1–3 days). Your fireplace opening must be at least 23¼″ wide, 21″ high and 15″ deep.
Buying the insert and the liner together? Our Escape 1800-I and Escape 1500-I bundles, and our Century CW2100, CW2800 and CW2900 bundles, pair the insert, faceplate and liner kit at a package price, saving up to $278 — see the wood insert guide.
Pellet appliances are different
A pellet insert vents through a 3-inch flexible liner, not a 6-inch one — the ComfortBilt HP22i liner kit ($489) is the purpose-built version. Freestanding pellet stoves usually vent straight out a wall instead. Our pellet vent pipe guide covers that side with full parts pricing.
Insulated or uninsulated?
Insulating a liner keeps the flue gases hotter on the way up. Hotter gases mean stronger draft, faster warm-up, and less creosote condensing inside the liner — which is why insulation is most valuable on exterior chimneys and in cold climates, where an uninsulated liner sheds heat into cold masonry. Whether insulation is required in your install depends on the liner's listing, the condition of your chimney, and local code, so follow the installation instructions that come with the liner and, when in doubt, have a chimney professional confirm.
If you'd rather not wrap the liner yourself, the Forever Flex 6" pre-insulated tee kit and pre-insulated appliance connector kit arrive insulated from the factory.
Can I install a liner myself?
A straight-shot reline is one of the more DIY-able chimney jobs: the liner feeds down from the roof, connects at the bottom, and caps at the top. It's a two-person job because of roof work and the length of the liner. Offsets, damaged chimneys, or any uncertainty about the flue's condition are where you bring in a chimney sweep — and a pre-install inspection is a good idea on any older masonry chimney regardless. Follow the kit's installation instructions and your stove manual throughout; they govern the details of your specific install. Our wood stove installation guide covers where relining fits in the wider project.
Frequently asked questions
What size chimney liner do I need for a wood stove?
Match the liner to your stove's flue collar diameter. The Drolet and Englander wood stoves and inserts we carry use a 6-inch collar, so a 6-inch liner is the match. Never size down, and don't size up — an oversized flue cools the exhaust and weakens draft. Confirm the collar size in your stove's manual.
Do you sell 4-inch chimney liners?
Yes. We stock 4-inch stainless flex kits in 25 ft (VOLKA-425, $399) and 35 ft (VOLKA-435, $519), which suit 4-inch appliances such as the Drolet ECO-65R venting into masonry. We also stock 316Ti Forever Flex kits in 4, 5, 5.5, 6, 7 and 8 inches.
What grade of stainless steel chimney liner do I need?
For wood-burning appliances, 304 or 304L stainless is the standard and appropriate grade, and it is what our Vortex kits use. Our Forever Flex kits are 316Ti, which also covers coal, oil and gas. 904 grades are typically specified for some high-efficiency gas and oil appliances. If you burn wood, paying for 904 buys resistance you will not use.
Do I need a chimney liner for a wood insert?
Yes. Drolet and Englander insert manuals call for a full-height liner from the insert collar to the top of the chimney, and inspectors expect one. Venting an insert into an unlined or partially lined masonry chimney hurts draft and lets creosote build in the masonry.
How much does it cost to reline a chimney?
Professional chimney liner installation runs $1,500 to $4,000 per HomeGuide's 2026 figures, with a stainless steel reline specifically at $900 to $3,800; HomeAdvisor puts the average around $2,500. Masonry repairs, offsets and difficult roof access push it higher. Doing a straight-shot reline yourself with a complete kit costs $399 to about $1,100.
Is it cheaper to install a chimney liner yourself?
Considerably — a straight, accessible flue is a realistic two-person DIY job, and doing it yourself saves roughly $1,000 to $3,000 against an installed quote. Offsets, damaged flues and older chimneys of unknown condition are jobs for a chimney sweep, and no saving is worth a liner that fails an inspection.
How much does a chimney liner cost?
Our complete stainless steel kits run from $399 for a 4-inch 304 kit to about $1,100 for a long 316Ti kit, and from $1,027 for a pre-insulated kit, including top plate, cap and connector hardware, with No Sales Tax and free shipping. That is the DIY material cost; see the two questions above for what professional installation adds.
Should a chimney liner be insulated?
Insulation keeps flue gases hot, which improves draft and reduces creosote — most valuable on exterior chimneys and in cold climates. Whether it's required depends on the liner's listing, your chimney's condition, and local code, so follow the liner's installation instructions.
How do I know if I need the 25-foot or 35-foot kit?
Measure from the liner connection at the stove or insert to the top of the chimney and round up. Excess liner can be trimmed at install; a liner that comes up short can't be stretched.
Can I install a chimney liner myself?
Straight runs are a realistic two-person DIY job — feed the liner from the roof, connect at the bottom, cap at the top. Offsets, damaged flues, or older chimneys of unknown condition are jobs for a chimney sweep, and a pre-install inspection is smart on any older masonry chimney.
Insulation and liner options we carry: HomeSaver FlexWrap insulation blanket with ArmorMesh to hold it in place, the all-in-one Super Wrap insulation kit, factory pre-insulated Forever Flex liner, and Rhino Rigid 316L rigid liner for straight chimneys. Fittings for every liner are in chimney liner parts.
Related guides
- Wood Stove Pipe Installation: Parts and Prices
- Chimney Caps: When to Replace One
- Wood Burning Fireplace Inserts
- Faceplates and Trim Kits for Wood Inserts
- Pellet Stove Vent Pipe: Parts and Prices
- Wood Stove Flue Guide: Sizing and When to Reline
Keeping a stainless liner clean: use a poly chimney brush sized to the liner, never a wire brush, which can scratch it. Oval liners need an oval liner brush. See all chimney brushes and sweep rods.
Written and reviewed by the StoveSource team. We sell and ship every liner kit covered here.