Chimney Flue Repair Cost Calculator

By Michael Woo · Updated June 2026

The national estimate is adjusted by your state's overall price level (BEA Regional Price Parities, 2022, U.S.=100). This is a cost-of-living proxy applied to the national chimney flue repair price — not a per-state chimney flue repair quote. Always get local quotes before buying.

$2,000–$6,000 20 linear ft · $100–$300/linear ft flue liner
BLS OEWS 47-4011 Construction and Building Inspectors — verified 2025-04, updates annual

Pro tips

Match the Flue Liner Material to the Fuel Type — Wrong Material Causes Rapid Failure

Gas appliances producing 300–400°F exhaust use aluminum liners at $15–$25/lft; wood-burning appliances producing 1,000–2,000°F creosote exhaust require 316Ti stainless at $30–$55/lft; oil appliances producing sulfuric acid condensate need AL29-4C at $45–$70/lft. Installing aluminum on a wood-burning fireplace saves $500–$1,000 upfront but corrodes through in 3–5 years, costing $2,500–$4,500 to remove and replace. A 30-foot chimney in the correct material runs $900–$2,100 for gas, $900–$1,650 for wood, or $1,350–$2,100 for oil in materials alone.

Size the Replacement Liner to the Appliance BTU Rating, Not the Existing Flue Opening

An oversized liner matching the old 8×8 or 8×12 clay tile diameter instead of a modern furnace's required 4–5 inches cools flue gases too rapidly, causing condensation that deposits corrosive moisture on liner walls. A properly sized 6-inch stainless steel liner for a wood stove costs $30–$55/lft versus $45–$80/lft for an oversized 8-inch liner — correct sizing saves $450–$750 in material on a 30-foot run. The appliance manufacturer's installation manual specifies the required diameter in inches; a 4–6 inch collar on a modern gas insert versus an 8-inch legacy opening is a code-critical mismatch that costs $1,500–$3,000 to redo.

Video-Inspect the Existing Flue Before Choosing a Repair Method

A chimney camera inspection costs $150–$350 and reveals crack locations, joint separation, collapsed tiles, and obstructions throughout the full flue height — without it, choosing the wrong repair method wastes thousands. A flue with 2–3 cracked tiles but intact joints can use a HeatShield poured liner at $2,000–$4,000; widespread joint separation requires full stainless relining at $2,500–$5,500. Attempting the cheaper poured liner in a flue with displaced tiles creates carbon monoxide voids and wastes the $2,000–$4,000 already spent.

Hidden costs

Permits and reline inspection

Flue repair quotes rarely include the mechanical or fuel-appliance permit, which runs $75–$250 depending on jurisdiction, and a fuel-conversion reline (wood-to-gas, or adding a stove) almost always triggers one. A UL 1777 liner serving a solid-fuel appliance gets a rough and final inspection in most 2021 IRC jurisdictions, and a failed final forces a re-inspection fee of $50–$100 plus a return trip at $90–$140/hr (BLS OEWS 47-4011 median $22.15/hr). Some counties also require a Level 2 NFPA 211 camera inspection at $150–$300 before issuing the permit — separate from the diagnostic the contractor runs to quote the job.

Debris disposal and creosote handling

Tear-out reline pricing often excludes haul-off of broken clay tile and built-up creosote, which crews bill at $150–$400 per job; a stainless reline of a collapsed flue generates 200–400 lbs of tile rubble that cannot go in standard household trash. Stage 3 glazed creosote is treated as a flammable hazard requiring sealed-bag disposal, and markets with transfer-station minimums add a $40–$80 dump fee per load. A pre-reline cleaning to bare tile adds $200–$350 before any liner drops, since stainless cannot be installed over heavy glaze.

Roof access and staging prep

A top-down stainless install on a roof over 6:12 pitch needs roof jacks, planks, and a tie-off anchor that add $300–$600 in setup, and a chimney rising more than 4 ft above the ridge needs scaffold staging at $400–$900 for a multi-day reline. Crews on slate or clay-tile roofs charge a fragile-surface premium of $150–$300 because foot traffic cracks tiles. A ground-level mobilization minimum of $400–$600 applies on short flues where the per-foot band would otherwise underprice the trip, and power-line clearance near the chimney can force a hand-rigged install that adds crew-hours at $90–$140/hr.

Adjacent masonry and cap repairs

Flue repair frequently surfaces shell damage the flue quote does not cover: a cracked crown gets re-poured for $200–$500, a rusted chase cover or new top plate runs $150–$400, and spalled brick at the chimney top often needs $500–$1,200 per section before a liner termination can seal. Flashing at the roof line adds $300–$700 to reflash, and a new stainless cap or rain pan to terminate the liner runs $100–$300 installed. These adjacent lines routinely add 20–40% on top of the per-foot flue band when the chimney has gone years without service, and skipping them voids the liner warranty in most cases.

Rookie mistakes

Applying Flue Sealant Over Cracked Clay Tiles Without Addressing Structural Displacement

Brush-on flue sealants ($200–$600 for a full flue) work only on hairline cracks under 1/16 inch in properly aligned tiles; tiles shifted more than 1/4 inch allow flue gases to escape into the chimney chase, creating a carbon monoxide intrusion risk. Building codes require a continuous gas-tight flue liner per NFPA 211 section 14.3, and sealant over structurally failed tiles fails the chimney inspection — triggering a $50–$100 re-inspection fee plus mandatory relining. If tiles are displaced more than 1/4 inch, the only code-compliant repair is a full relining at $2,500–$5,500.

Relining Only the Portion of the Flue Above the Roofline

The concealed flue section through the attic typically runs 8–15 feet and accumulates 2–3× more condensation than the above-roof section because attic temperatures average 20–30°F cooler, accelerating tile spalling. Relining only the top 5–8 feet of a 25-foot flue costs $500–$1,200 but leaves 17–20 feet unprotected; when the lower section fails in 3–5 years, removing the partial liner and completing the job totals $3,500–$6,500 — $1,000–$2,000 more than a full liner initially. A full-length stainless liner covering all 20–30 feet from the appliance connection to the chimney cap carries a 20–25 year manufacturer warranty; a partial repair carries none.

Ignoring the Chimney Cap and Rain Entry as the Root Cause of Flue Deterioration

A missing cap deposits roughly 1/3 gallon of water per storm event directly onto clay tile liner from 1 inch of rain on an 8×8-inch flue opening, accelerating damage at 5–10× the rate of a capped flue. After 3–5 years of uncapped exposure, full relining costs $2,500–$5,500. A stainless chimney cap with spark screen costs $150–$400 installed — if the mason's scaffold is already up for flue repair, adding the cap protects a $3,000–$5,000 liner investment at zero extra access cost.

Example project costs

Short Chimney (15 lft)

15 linear ft, single-story gas flue

Joint tuckpointing (mortar only)$1,500-$2,250
Cast-in-place resurfacing alternative$2,250-$3,000
Stainless steel liner replacement$3,000-$4,500
Mobilization minimum (short flue)$400-$600
Total$1,500-$4,500

Standard (20 lft)

20 linear ft, standard masonry flue

Joint tuckpointing (mortar only)$2,000-$3,000
Cast-in-place resurfacing alternative$3,000-$4,000
Stainless steel liner replacement$4,000-$6,000
Tile tear-out + creosote disposal$350-$750
Total$2,000-$6,000

Two-Story (30 lft)

30 linear ft, two-story wood-stove flue

Joint tuckpointing (mortar only)$3,000-$4,500
Cast-in-place resurfacing alternative$4,500-$6,000
Stainless 0.020-in liner + insulation$6,000-$9,000
Scaffold staging + fall protection$700-$1,400
Total$3,000-$9,000

What NOT to build with chimney flue repair

Don't use chimney flue repair for: Chimneys with confirmed creosote buildup exceeding Stage 3 (glazed creosote)

Stage 3 glazed creosote burns at 1,000°F+ during a chimney fire; a new liner installed over it creates an insulated fuel layer between liner and flue wall. Professional cleaning to Stage 1 costs $200–$500 and is a non-negotiable prerequisite before any liner installation.

Don't use chimney flue repair for: Unlined chimneys built before 1940 that serve as the sole structure supporting the roof

Pre-1940 chimneys often carry roof loads as structural masonry piers; drilling or inserting liners risks compromising that structure, and a structural engineer evaluation runs $300–$600 before any flue modification can proceed.

Flue Repair and Relining Methods Compared

OptionPros & ConsBest For
Stainless Steel Flexible LinerMost common method; $2,500–$5,500 installed; fits any flue shape; 20-year+ warranty; all-fuel rated (316Ti); requires top and bottom connectorsAny chimney with multiple cracked tiles, displaced joints, or existing liner failure regardless of fuel type
HeatShield Poured-In-Place LinerCosts $2,000–$4,000; builds new liner inside existing tiles; requires intact tile alignment; 20-year warranty; cannot be inspected after installationChimneys with cracked but properly aligned tiles where the existing tile structure can serve as a form
Clay Tile Replacement (Individual Tiles)Costs $150–$500 per tile replaced; matches original construction; limited to accessible tiles near top or bottom; mortar cure time 7+ daysChimneys with 1–3 damaged tiles near the top that can be accessed from the chimney top without demolishing surrounding masonry
Cast-In-Place (Supaflu/Ahrens) SystemCosts $3,000–$6,000; creates monolithic liner with no joints; insulates the flue; adds structural strength to chimney; permanent installationDeteriorated chimneys that need both flue repair and structural reinforcement of the masonry column

Tools required

A DIY reline needs a flue camera ($150–$400 to buy or $50/day rented) to confirm tile condition before committing, plus a stainless liner kit (316Ti or 304, sized 5–8 in) running $300–$800 for a 20-lft length with top plate and tee. Tuckpointing the joints instead needs refractory mortar ($15–$30/bag), a tuck-point trowel, a 4-inch grinder with a tile-rated diamond wheel ($30–$60), and a flue brush to clear debris. Roof work demands a tie-off harness ($100–$200), roof jacks, and planks; a cast-in-place pour at $150–$200/lft is contractor-only because Supaflu and HeatShield require licensed-applicator equipment.

Skill level

Chimney flue repair sits at advanced DIY for a stainless reline and intermediate for joint tuckpointing, with most homeowners completing a straight 20-lft drop in 8–14 hours. Dropping a flex liner down a straight 20-lft flue is mechanically simple, but the insert must be UL 1777 listed for solid fuel, sized to the appliance collar, insulated where clearances fall under NFPA 211's 2-in minimum, and terminated with a sealed top plate. Get the gauge wrong — 0.016-in on a high-burn wood stove that calls for 0.020-in — and the liner fails inside a season. The fuel-conversion case is the hard stop: relining wood-to-gas pulls a permit, an inspection, and a draft test that 90% of jurisdictions will not sign off on as an owner-install.

Time required

A DIY stainless reline of a straight 20-lft flue runs 8–14 hours for one person across 2 days: a day to camera-inspect, sweep to bare tile, and stage the roof, then a day to drop, insulate, and terminate the liner. A tuckpointing-only job on accessible upper joints runs 4–8 hours but balloons if joints deep in the flue force partial dismantling. Tear-out of a collapsed tile flue before relining adds 6–10 hours of debris-by-debris demolition that contractors handle in 3–4 hours with the right gear. A permitted reline then waits 3–7 days on a scheduled final before the appliance can fire, and cold weather extends mortar cure on tuckpointing past the 24-hour minimum.

When DIY saves vs when it costs more

DIY saves most on a straight, intact-tile flue needing a simple stainless drop: skipping the $90–$140/hr crew on an 8–12 hour job cuts $700–$1,700 off a $4,000–$6,000 quote, leaving mostly the $300–$800 liner kit. DIY costs more the moment the flue is offset, collapsed, or fuel-converting — an offset flue needs a rigid-to-flex transition most homeowners botch, and a wrong bend kinks the $300–$800 liner kit. A fuel-conversion reline that fails the draft test because the liner was undersized by even 1 inch means a licensed contractor redoes it at full price ($2,500–$5,500) plus the cost of the wasted $300–$800 kit. The break-even is roughly a 15-lft straight gas-only flue; above that height, or any solid-fuel or conversion case, the inspection risk erases the labor savings.

Repair methods, liner gauge, and NFPA 211 standards

Chimney flue repair splits across 3 method bands tied to flue condition: joint tuckpointing at $100–$150/lft when only mortar joints have eroded; cast-in-place resurfacing (Supaflu or HeatShield) at $150–$200/lft when tiles are spalled but the masonry shell holds; and full stainless steel liner replacement at $200–$300/lft when tiles have collapsed or the flue must serve a new appliance (BLS OEWS 47-4011 median $22.15/hr). Liner gauge is set by burn load under NFPA 211: 0.016-in stainless suits gas and light wood use, while 0.020-in is required for high-burn wood stoves driving flue-gas temperatures past 1,000°F. UL 1777 listing is mandatory for any insulated insert serving a solid-fuel appliance, and insulation wrap adds $8–$12/lft where clearances fall under the NFPA 211 2-in minimum.

Labor rates and regional cost factors

Crews bill against BLS OEWS 47-4011 (chimney sweeps and repairers median $22.15/hr), but a 2-person crew with rooftop staging and a flue camera bills out at $90–$140/hr loaded. A 20-lft tuckpoint job runs 6–9 crew-hours; a stainless reline of the same height runs 8–12 crew-hours once tile tear-out is included. Regional spread is wide: Northeast metros with steep slate roofs push the $300/lft ceiling, while single-story Sun Belt flues land near $100–$150/lft, and a September quote runs 15–20% over an April quote as reline demand spikes before heating season. Coastal salt-air counties effectively mandate 316Ti over 304 stainless, adding $3–$5/lft in material.

Project scope and sizing rules by flue height

Standard masonry chimneys run 15–20 lft from smoke chamber to cap; 2-story homes with a basement appliance reach 28–32 lft. Below 15 lft a mobilization minimum of $400–$600 dominates, and the per-foot rate loses meaning; from 15–25 lft the band holds — a 20-lft stainless reline at $200–$300/lft totals $4,000–$6,000. Above 30 lft, a top-down install over a steep roof adds $300–$500 in fall-protection and staging. A 7×11 clay tile takes a 6-in round insert, while a 13×13 fireplace flue needs an 8-in oval liner costing $4–$7/lft more in stainless; multi-flue chimneys price each flue separately.

Cost drivers and code exceptions

A collapsed tile flue requiring demolition debris vacuumed out tile by tile runs the $250–$300/lft ceiling; an intact flue taking a cast-in-place pour stays near $150–$200/lft since nothing is removed. Jurisdictions on the 2021 IRC require a UL 1777 listed liner for any fuel-conversion reline, blocking cheaper unlisted aluminum flex that some markets still allow on gas-only flues. Coastal salt-air counties effectively mandate 316Ti over 304 stainless, adding $3–$5/lft, and historic-district chimneys may bar a visible top plate, forcing an interior-only termination that adds $200–$400 in custom flashing. Where the flue clears framing by under 2 in, NFPA 211 forces an insulated liner regardless of fuel — adding $8–$12/lft even on a budget reline.
How this is calculated

Formula: linear ft × $100–$300/linear ft flue liner repair (BLS OEWS 47-4011)

InputValueUnit
Flue height 20 linear ft
Grade 2

Frequently Asked Questions

How much does Chimney Flue Repair cost per linear foot?

$100–$300 per linear foot depending on method: joint tuckpointing at $100–$150/lft, cast-in-place resurfacing at $150–$200/lft, and full stainless steel liner replacement at $200–$300/lft (BLS OEWS 47-4011 chimney sweeps/repairers median $22.15/hr). A standard 20-lft flue lands at $2,000–$6,000 total across those bands.

What does a Chimney Flue Repair cost on a standard 20-foot chimney?

$2,000–$6,000 for a 20-linear-ft flue: tuckpointing the joints runs $2,000–$3,000, a HeatShield cast-in-place pour runs $3,000–$4,000, and a full stainless reline with tear-out and top plate runs $4,000–$6,000 (BLS OEWS 47-4011 median $22.15/hr). Collapsed tile requiring full demolition adds $500–$1,500 in debris removal and pushes the total toward $7,500.

Why is a stainless steel Chimney Flue Repair more expensive than tuckpointing?

$200–$300/lft for stainless versus $100–$150/lft for tuckpointing because stainless includes tile tear-out, a UL 1777 listed 316Ti or 304 insert, insulation wrap where NFPA 211 clearances require it, and a sealed top plate. Tuckpointing only repacks eroded mortar joints between intact clay tiles using a $15–$30 bag of refractory mortar — no liner material and no demolition labor.

What stainless liner gauge does a Chimney Flue Repair need for a wood stove?

0.020-in stainless for high-burn wood stoves per NFPA 211, versus 0.016-in for gas and light wood use. The heavier gauge survives flue-gas temperatures past 1,000°F and must carry a UL 1777 listing sized to the appliance collar, adding $8–$12/lft for the required insulation wrap.

Is Chimney Flue Repair different from chimney masonry shell repair?

Yes — Chimney Flue Repair is interior liner work at $100–$300/lft, while exterior masonry shell repair runs $500–$1,200 per section on the chimney-repair-cost-calculator. Spalled brick, a cracked crown, and a rusted chase cover all fall under the exterior shell scope and add $300–$800 each; both interior and exterior repairs are frequently needed at once on a neglected chimney.

Does a Chimney Flue Repair require a permit and inspection?

$75–$250 for the permit in most 2021 IRC jurisdictions whenever the reline serves a fuel conversion or solid-fuel appliance. A UL 1777 liner pulls a rough and final inspection, and a failed final costs $50–$100 in re-inspection fees plus the crew's return trip at $90–$140/hr.

Sources

  1. BLS OEWS 47-4011 Construction and Building Inspectors — verified 2025-04, updates annual