Why is one relining quote half the size of another for the same chimney?

Usually because they are not quotes for the same job. The common differences are the alloy, whether the liner is insulated and over what length, the diameter and where it came from, whether damaged clay tile is being removed or left in place, and whether anyone has scanned the flue. Put the two quotes side by side on those five points and the spread normally explains itself.

Is a 304 stainless liner a false economy compared with 316?

Not by itself. Manufacturer manuals assign the grades by class of service — 304 and 304L for wood, pellet and fireplace appliances, 316 for wood, coal, oil, gas and solid fuel, and AL 29-4C for high-efficiency condensing appliances only, never for wood. A higher grade than the manual calls for buys nothing extra; a lower one than it permits is not a saving, because it puts the installation outside the listing.

Do I really have to pay for an inspection before anyone can quote a liner?

The national standard for chimneys names relining as one of the circumstances calling for a Level 2 inspection, and a Level 2 requires the internal surfaces of the flue liners to be examined with image-scanning equipment. A quote written without that is priced around an unknown. Whether it is legally required depends on locally adopted codes, so confirm with your city or county building department.

Why does a liner quote include sweeping when I only asked for a liner?

Because the liner manufacturers require it. Their installation instructions call for creosote, soot and debris to be removed and the chimney confirmed structurally sound before a liner is installed, and meeting those prerequisites is a condition of both the listing and the warranty. A quote that leaves the sweep out is not covering less work; it is covering the same work with the paperwork weakened.

At what point does relining stop being worth it compared with rebuilding?

The turning point is the condition of the masonry, not the length of the flue. Manufacturers do not permit lining a chimney that is not structurally sound, so failing brick and mortar has to be dealt with first. In Seattle there is a second trigger: the SDCI rule for masonry chimney work states that where repairs reach below the top of the smoke chamber, the smoke chamber and chimney must be rebuilt entirely to current code. Requirements change and depend on the property — confirm with SDCI before work starts.

How do I compare a cast-in-place quote against a stainless liner quote?

Start by asking which of the code-recognized linings each one is, since the code lists a short set — ASTM C315 clay tile, a listed system complying with UL 1777, a listed factory-built chimney unit, or another approved material rated to 1,800 degrees F. Then apply the same three tests an inspector would: installed per the manufacturer's instructions, the right material for the class of service, and properly sized. Cast-in-place is additionally judged on thickness and a surface free of large irregularities.

Can a factory-built metal chimney be relined, or does it have to be replaced?

It can usually be relined, but the size limit is the thing that decides the cost. DuraVent's supplemental instructions for relining an existing factory-built chimney for solid fuel cap the liner's inside diameter at 2 inches smaller than the inside diameter of the existing chimney, and require the chimney to be cleaned and checked for structural defects first. If the diameter your appliance needs will not fit inside that limit, the conversation turns into chimney replacement. Other manufacturers set their own limits, so the governing document is the product's own instructions.

Cost guide

Chimney liner cost in Seattle: what actually drives a relining quote

You are not really buying a liner. You are buying the diagnosis that decides which liner, the labor to get the correct one down a flue that was never built to receive it, and the listed components that make the finished assembly usable.

What follows is the structure of the number rather than the number: where the money goes, which quiet substitutions make a quote smaller without making the job smaller, and what to ask so two quotes describe the same work.

Reviewed by Chimney4u editorial team · Last updated 2026-08-27

Where the money in a relining quote actually goes

A relining quote reads like a price for a pipe. It is mostly a price for diagnosis, access, and the parts that make the pipe usable. Liner is a stocked product sold by the foot; the flue is the variable, and no two flues are the same.

The diagnosis. The national standard calls for a Level 2 inspection before a flue is relined, including an image scan of the liner's inside surfaces. It is what turns the rest of the quote from a guess into a specification.
Getting the flue ready to receive a liner. Manufacturers make a swept, structurally sound flue a condition of the installation and of the warranty. It is not an add-on to be negotiated off the bottom of a quote.
Clearing a path for the required diameter. If damaged tile, an offset, or a narrowing smoke chamber will not pass the size the appliance needs, that material has to come out from inside a masonry shaft.
The listed system, not just the liner. Insulation, top plate, storm collar, rain cap and the appliance connector are all part of the assembly the listing covers. Substituting outside it is where a quote gets cheaper and the paperwork stops meaning much.

Why two quotes for the same flue are not for the same job

The spread between relining quotes is rarely margin. It is specification. Six things can be changed without ever being mentioned, and each makes the number smaller by making the job different.

The alloy is never named. A line that says only "stainless steel liner" has not told you which stainless, and alloy is assigned by fuel in the manufacturer's manual.
The insulation is left off. Insulation is usually what earns a liner its reduced-clearance listing and what keeps flue gas above dew point. Leaving it off yields a smaller number and a different system.
The diameter is the one that fits. A smaller liner slides past an obstruction without demolition. If it ends up smaller in area than the appliance outlet collar, a code floor has been crossed.
The old clay tile stays in place. Leaving cracked tile in place can be correct, but only if the required diameter still passes and the liner's own instructions allow it.
Nobody has looked inside the flue. Without a camera scan there is no record of what the liner is going into. The unknown transfers to you and arrives later as a change order.
It is quietly a gas-only liner. After a gas conversion this is often right. It also narrows what the flue may ever serve, and code requires a permanent label at the connector saying so.

An oversized flue is a cost problem, not an upsell

The intuition is that a bigger flue is a bonus with nothing to pay for. The physics runs the other way. Flue gas stays a gas only above its dew point, which one manufacturer approximates at 128 degrees F. A flue with more volume than the appliance can heat cools that gas, and what comes out is condensate on the inside of your chimney.

Condensate costs money twice. It attacks the liner you just paid for, because ordinary household air carries chlorides from carpeting, paints, thinners and detergents that combine with condensate into aggressive acids. And a cool flue lays down creosote faster on wood, shortening the service interval for the life of the system. A liner chosen because it is the largest that will fit is the cheapest decision to make on site, and you carry it afterwards.

Four findings that change the order of magnitude

Most of a relining quote moves within a band. Four findings move it out of the band entirely, and each is knowable before the liner is ordered — which is why they belong in the inspection, not in a mid-job phone call.

The required diameter will not pass. Breaking out clay tile or opening an offset is demolition inside a masonry shaft, worked largely blind from the top. It is a different job from dropping a liner.
The chimney is not sound enough to line. A liner cannot rescue failing masonry, and manufacturers make a sound chimney a condition of installation. The liner becomes the second scope on the invoice, not the first.
The local chimney rule pulls the masonry in. In Seattle, unreinforced masonry chimney work sits under a specific SDCI rule whose triggers can decide whether you are lining a chimney or rebuilding one.
It is a factory-built chimney, not masonry. A listed metal chimney can be relined, but the liner has to be meaningfully smaller than the existing chimney's inside diameter, which can put the required size out of reach.

What moves the price

Which of the code-recognized linings is usedchanges the material and the trade: Clay tile relining, a listed stainless system and a cast-in-place pour are three different operations with different crews, different day counts and different equipment on site. Comparing a quote for one against a quote for another as if they were the same product is the most common way homeowners misread a spread.
The alloy, which the fuel decideschanges the material: Manufacturer manuals assign stainless grades by class of service, so the fuel you burn narrows the choice before anyone quotes. Paying up for an alloy the manual does not call for buys nothing; installing one it does not permit is not a saving, because it is outside the listing that makes the installation compliant.
Insulation, and how much of the run it coversadds material along the entire length: Insulation is normally the condition on which a reduced-clearance listing depends, and it is what holds flue gas above dew point. A quote should say what insulation and over what length, because 'insulated liner' can mean the full run or the part someone could reach.
Whether the flue has to be opened up to take the correct diameterturns a rigging job into a demolition job: If damaged tile or an offset blocks the size the appliance requires, the tile is broken out from inside the chimney. This is the largest single swing in a relining quote and the one most often left as an assumption rather than a priced line.
Whether this is a gas conversion or a wood insertchanges the specification and what the flue may serve later: A gas conversion usually points at a smaller, uninsulated liner and a permanent usage label restricting the flue; a wood insert points at a full-length insulated system in a heavier alloy. The wood path costs more and keeps more options open, and that trade-off belongs in the decision, not just in the price.
How much diagnosis has already been paid formoves a cost, it does not remove it: A camera scan and measurements are what allow the diameter, the insulation and the tile question to be settled on paper. A quote issued without them was not cheaper to produce by accident: the work has been deferred rather than deleted, and it reappears once the flue is open.
What the chimney needs before a liner is allowed to go inadds a separate scope ahead of the liner: Sweeping, masonry repair, a crown, or flashing work can each be a prerequisite rather than an extra. The useful question is not whether these are included but whether they have been priced separately and honestly, because bundling them hides which one is actually driving the number.
Whether the quote is a fixed scope or an allowancedecides who carries the unknown: A fixed scope built on a scan puts the risk of a surprise on the contractor. An allowance, or a verbal 'we will see when we get in there', puts it on you. Two quotes can differ mostly because one of them has already absorbed a risk the other has left open.

Why there is no number on this page

We have not published a price range here, because we have not got one we could stand behind for a chimney we have not seen. What we can do is look at yours, show you the photographs, and give you a written scope with a real figure on it before anything starts.

Get a written scope

What a fair quote includes

A Level 2 inspection with a camera scan of the flue interior, and the measurements the quote was built from — flue height, interior dimensions, offsets and the appliance outlet collar
The liner written out as a specification rather than a description: material, alloy, diameter, length and the listing standard, not simply 'stainless steel liner'
The insulation type and the length of run it covers, stated explicitly, together with the clearance the listing depends on
Sweeping the flue clean of creosote, soot and debris before installation, which manufacturers make a condition of the listing and the warranty
Removal of damaged tile or an obstruction where the required diameter will not otherwise pass — priced as its own line, or explicitly excluded so you can see the assumption
The listed termination and connection components: top plate, storm collar, rain cap, and the tee or appliance adapter the manufacturer specifies
A draft check on completion, and the product listing and warranty paperwork for what was actually installed
Photographs of the chimney before and after, from the same angles where that is practical
A plain statement of what is excluded and would be quoted separately — masonry repair, crown work, flashing, the appliance itself, permits
A written scope and price you approve before anything is ordered or started

Questions to ask before you accept a quote

Which alloy is this liner, and where in the manufacturer's installation instructions is that alloy approved for the fuel I burn?
What diameter did you size this to, and did the size come from the appliance outlet collar or from what fits down the existing flue?
Is the liner insulated, over what length, and does the clearance you are relying on depend on that insulation being there?
Has anyone put a camera down this flue, and can I see the scan or the still images from it?
Does this quote assume the existing clay tile stays in place, and what changes in scope and schedule if it has to come out?
Will this liner limit what appliance can ever be connected to this flue, and will a permanent usage label go up at the connector?
If the masonry turns out to need repair before the liner can be installed, is that covered by an allowance here or would it be a separate quote?
Who is responsible for determining whether a permit is required, and has anyone checked the rule that applies to this chimney?
What is your Washington contractor registration number, so I can look up its status with the Department of Labor and Industries myself?

Common questions

Why is one relining quote half the size of another for the same chimney?: Usually because they are not quotes for the same job. The common differences are the alloy, whether the liner is insulated and over what length, the diameter and where it came from, whether damaged clay tile is being removed or left in place, and whether anyone has scanned the flue. Put the two quotes side by side on those five points and the spread normally explains itself.
Is a 304 stainless liner a false economy compared with 316?: Not by itself. Manufacturer manuals assign the grades by class of service — 304 and 304L for wood, pellet and fireplace appliances, 316 for wood, coal, oil, gas and solid fuel, and AL 29-4C for high-efficiency condensing appliances only, never for wood. A higher grade than the manual calls for buys nothing extra; a lower one than it permits is not a saving, because it puts the installation outside the listing.
Do I really have to pay for an inspection before anyone can quote a liner?: The national standard for chimneys names relining as one of the circumstances calling for a Level 2 inspection, and a Level 2 requires the internal surfaces of the flue liners to be examined with image-scanning equipment. A quote written without that is priced around an unknown. Whether it is legally required depends on locally adopted codes, so confirm with your city or county building department.
Why does a liner quote include sweeping when I only asked for a liner?: Because the liner manufacturers require it. Their installation instructions call for creosote, soot and debris to be removed and the chimney confirmed structurally sound before a liner is installed, and meeting those prerequisites is a condition of both the listing and the warranty. A quote that leaves the sweep out is not covering less work; it is covering the same work with the paperwork weakened.
At what point does relining stop being worth it compared with rebuilding?: The turning point is the condition of the masonry, not the length of the flue. Manufacturers do not permit lining a chimney that is not structurally sound, so failing brick and mortar has to be dealt with first. In Seattle there is a second trigger: the SDCI rule for masonry chimney work states that where repairs reach below the top of the smoke chamber, the smoke chamber and chimney must be rebuilt entirely to current code. Requirements change and depend on the property — confirm with SDCI before work starts.
How do I compare a cast-in-place quote against a stainless liner quote?: Start by asking which of the code-recognized linings each one is, since the code lists a short set — ASTM C315 clay tile, a listed system complying with UL 1777, a listed factory-built chimney unit, or another approved material rated to 1,800 degrees F. Then apply the same three tests an inspector would: installed per the manufacturer's instructions, the right material for the class of service, and properly sized. Cast-in-place is additionally judged on thickness and a surface free of large irregularities.
Can a factory-built metal chimney be relined, or does it have to be replaced?: It can usually be relined, but the size limit is the thing that decides the cost. DuraVent's supplemental instructions for relining an existing factory-built chimney for solid fuel cap the liner's inside diameter at 2 inches smaller than the inside diameter of the existing chimney, and require the chimney to be cleaned and checked for structural defects first. If the diameter your appliance needs will not fit inside that limit, the conversation turns into chimney replacement. Other manufacturers set their own limits, so the governing document is the product's own instructions.

The service itself

Relining replaces the flue's inner surface with a lining matched to the appliance connected to it. The material, diameter, listing and insulation are decided from an inspection and written into a scope you approve before anything is ordered, and the chimney is photographed before and after.

Chimney Liner Installation

Sources

Committee Input No. 9-NFPA 211-2024 [ Chapter 15 ] - First Draft Committee Input Statements, NFPA 211 A2026 cycle — National Fire Protection Association (NFPA). Accessed 2026-08-27.
Homeowner Resources - FAQ: What stainless steel liners require insulation? — Chimney Safety Institute of America (CSIA). Accessed 2026-08-27.
Standard Operating Procedure - Level 2 Inspection, Masonry Fireplace (Rev. 4/5/19) — Chimney Safety Institute of America (CSIA). Accessed 2026-08-27.
2021 Seattle Residential Code, Chapter 10, Chimneys and Fireplaces — Seattle Department of Construction and Inspections (SDCI), City of Seattle. Accessed 2026-08-27.
2021 Seattle Mechanical Code, Chapter 8, Chimneys and Vents, Sections 801.16 and 801.16.1 — Seattle Department of Construction and Inspections (SDCI), City of Seattle. Accessed 2026-08-27.
SDCI Director's Rule 07-2025, Alteration and Repair of Unreinforced Masonry Chimneys — Seattle Department of Construction and Inspections (SDCI). Accessed 2026-08-27.
SDCI Tip 303A, Common Seattle Residential Code Requirements — Seattle Department of Construction and Inspections (SDCI). Accessed 2026-08-27.
Flexible Chimney Liners: Ventinox, DuraFlex Pro, DuraFlex SW, DuraFlex 316, DuraFlex 304, TherMix, ProFoil - Installation Instructions — DuraVent. Accessed 2026-08-27.
DuraVent 1777 Liners - Factory-Built Chimney Relining for Solid Fuel, Installation Instructions — DuraVent. Accessed 2026-08-27.
Stainless Steel Flexible Liner - Installation Instructions and Maintenance Guide (Sizing the Proper Liner Diameter) — Selkirk Corporation (cross-checked against National Chimney Supply M-Flex instructions, CBIN-001). Accessed 2026-08-27.
Installation and Maintenance Instructions for Forever Flex / Pre-Insulated Forever Flex and ArmorFlex/Hybrid Liner - Insulation Requirements — Olympia Chimney Supply. Accessed 2026-08-27.
UL 1777 - Chimney Liners (Standard detail page) — UL Standards & Engagement. Accessed 2026-08-27.
Verify a Contractor, Tradesperson or Business — Washington State Department of Labor & Industries. Accessed 2026-08-27.

Next step

Start with an inspection

Tell us what you have noticed. We will look at the chimney, show you what we found, and put a price on the work before anything begins.

Request an inspection Call (206) 573-4487