How Much Does a Chimney Liner Cost in Toronto? (2026 Pricing)

Why so many Toronto chimneys need a liner

Toronto has a huge stock of chimneys built between 1900 and 1965, and most of them were built for one thing: a coal or oil furnace with a large, hot, corrosive flue gas stream. Clay tile liners from that era are usually intact enough to look fine from the roof, but decades of freeze-thaw cycles, chimney fires, or a switch to a cooler-burning gas furnace have left them cracked, oversized, or both.

A liner is not an upsell. It is the passage that carries combustion gases - carbon monoxide, moisture, and in wood-burning systems, creosote - safely out of the house. When a liner is cracked, missing sections, or too large for the appliance connected to it, gases can migrate into the wall cavity or condense inside the chimney and eat away at the mortar joints from the inside out. That is the single most common reason a 1950s Leaside or East York chimney needs a full rebuild by year 60 instead of year 100.

The three liner types used in the GTA

Flexible stainless steel

This is the liner installed in the vast majority of GTA relines. A continuous, corrugated stainless steel tube is fed down the chimney from the top, connected to the appliance at the bottom, and capped. It comes in single-wall and insulated versions, and in grades - AL29-4C stainless for gas and oil, or a heavier 316Ti grade for wood-burning appliances that see higher, more corrosive flue temperatures. Flexible liners are fast to install, do not require demolition, and are the standard fix for both furnace flues and wood fireplace flues.

Rigid stainless steel

Rigid sections are used less often in retrofits because a chimney rarely runs perfectly straight, but they are common in new chimney construction or where a chimney has a wide, straight interior that a flexible liner would sag or rattle inside of. Rigid liners cost slightly more per foot but last longer in high-heat wood-burning applications.

Clay tile and cast-in-place

Clay tile relining means removing the old tiles and installing new ones, which almost always requires opening part of the chimney chase - expensive and disruptive, and rarely the right call for a retrofit. Cast-in-place liners pour a lightweight refractory cement mix around an inflatable form inside the existing chimney, creating a smooth, insulated, seamless flue. Cast-in-place is the right choice when the masonry itself is structurally sound but the flue is badly out of round, has multiple offsets, or needs to be resized and insulated in one pass - it is also one of the few methods that can add real structural support to a deteriorating chimney.

Sizing: the part most quotes get wrong

A liner has to be sized to the appliance connected to it, not to the size of the existing masonry flue. This trips up a huge number of Toronto homeowners who upgrade an old 80% efficiency furnace to a mid-efficiency 80% unit, or add a gas fireplace insert into a chimney that used to vent a full masonry wood fireplace. An oversized flue cools flue gas too much before it exits, moisture condenses on the walls, and you get the sour, sooty smell that brings most liner calls to us in the first place.

CSA B149.1, the natural gas and propane installation code used across Ontario, sets out sizing tables based on appliance input (measured in BTU/h), vent height, and the number of elbows. A licensed gas technician calculates this before recommending a liner diameter - it is a calculation, not a guess, and it is the reason a fair quote includes the appliance's rated input in writing.

Relining a 1950s Toronto masonry chimney: what the job looks like

A typical call: a semi-detached home in East York or Scarborough, original clay-lined masonry chimney, coal-to-oil-to-gas conversion decades ago, furnace replaced two or three times since. The technician first runs a camera down the flue to check the tile joints, look for cracks, spalling, or offsets, and confirm there is no blockage or animal nest. If the tiles are intact and the flue is the right size, a liner may not even be strictly required for a gas appliance - but if the tiles are cracked, missing mortar, or the flue was ever used for wood burning and shows creosote glazing, relining is the fix.

1. Camera inspection of the full flue length from the top and, where possible, the cleanout at the base.
2. Measurement of the chimney's interior dimensions and confirmation of the connected appliance's BTU input.
3. Selection of liner diameter per CSA B149.1 sizing tables (for gas) or NFPA 211 (for solid fuel).
4. Removal of the old chimney cap and any obstructions at the top.
5. Feeding the liner from the top, connecting it to the appliance draft hood or connector at the bottom.
6. Insulating the liner where required (mandatory for most wood-burning installations, recommended for gas in unlined masonry).
7. Installing a new top plate, storm collar and cap sized to the liner.
8. Final draft test and, for gas appliances, a combustion analysis to confirm proper venting.

Gas conversions and gas fireplace inserts

Converting a wood-burning fireplace to a gas log set or a gas insert is one of the most common relining jobs across the GTA. The existing masonry flue, built for a large volume of wood smoke, is almost always too big for a gas appliance's much smaller, cooler flue gas volume. A properly sized flexible stainless liner - usually 4 to 6 inches in diameter depending on the appliance - solves the condensation and odour problems that come with venting a gas insert into an oversized open flue.

This is also where direct-vent gas fireplaces differ: many direct-vent units bring in outside combustion air and exhaust through a small dedicated pipe that may not even use the existing masonry chimney at all, run instead through the wall or up a smaller dedicated chase. Confirm with your installer which venting method your specific unit requires before assuming a chimney liner is even the right scope of work.

How chimney height and access affect the bill

Permits, TSSA and who is allowed to do this work

Gas-connected liner work in Ontario must be performed or supervised by a licensed gas technician (G2 or higher) registered with TSSA, the Technical Standards and Safety Authority. This applies whether the liner serves a furnace, a water heater, or a gas fireplace insert. Solid fuel liner installations fall under WETT (Wood Energy Technical Training) certification guidelines and NFPA 211 for construction and clearances.

A building permit from the City of Toronto or your local municipality is not typically required for a like-for-like liner replacement, but is required if the chimney itself is being rebuilt, resized structurally, or if the work is tied to a larger renovation. Always ask your contractor whether your specific job needs a permit before work starts - not after.

Red flags in a chimney liner quote

• No mention of the appliance's BTU input or the sizing calculation used to select the liner diameter.
• A single flat price with no distinction between single-wall and insulated liner, when your appliance type calls for insulation.
• Pressure to sign same-day after a free inspection that found 'urgent' cracks a homeowner cannot verify - ask to see the camera footage.
• No written liner material grade (AL29-4C vs 316Ti) despite a large price difference between the two.
• A quote for a full rebuild with no cast-in-place or reline alternative offered, when the masonry itself tested sound.
• No post-installation draft test or combustion analysis included for gas-connected liners.

How long a liner lasts

A properly installed stainless steel liner for a gas appliance typically lasts 15 to 20 years, and for a wood-burning appliance 15 to 25 years with annual sweeping and inspection. Clay tile, when undamaged and matched to the right appliance, can last the life of the chimney - which is exactly why so many original 1950s tiles are still doing their job today, provided nobody has connected an oversized modern appliance to them.

Getting an accurate number for your chimney

The two things that change a liner quote the most are the appliance connected to it and the chimney's height and condition, so any accurate number starts with a camera inspection, not a phone estimate. A WETT-trained or TSSA-licensed technician should be able to tell you the liner type, diameter and installed price on the same visit as the inspection.