Chimney Liners for Older Brick Flues and Gas Inserts

Short answer: a stainless steel liner run down an existing brick chimney costs $1,500 to $4,000 installed in HomeGuide's 2026 guide. It is needed when the clay flue tiles are cracked, missing or offset, or when a gas insert goes into an old masonry fireplace and the insert's maker calls for a liner sized to its vent.

Liners are an older-home job here. In Phoenix, Tempe, Glendale, Mesa and Sun City, many pre-1980 homes have masonry chimneys with clay tile flues that are now forty or more years old. Factory-built fireplaces in newer homes already have a metal flue as part of their listing, and those are repaired with the maker's own parts, not relined.

Signs you need this

• Cracked, broken or missing clay tile seen during an inspection or camera scan
• Pieces of tile or flaky material falling onto the smoke shelf or grate
• You plan to install a gas insert in a brick fireplace
• A past chimney fire, even a small one, in the fireplace's history
• Mortar gaps between flue tiles that let smoke into the masonry

How we do it

1. Inspect and, if needed, scanThe free inspection checks the flue as far as light reaches. If we suspect hidden damage, a camera scan is priced at the inspection.
2. Size the linerWe match diameter and length to the fireplace or insert, using the insert maker's venting instructions when there is one.
3. Run and connectThe stainless liner goes down from the top, connects to the insert or a smoke chamber adapter, and is sealed at the crown.
4. Cap and testA top plate and cap go on, and the fireplace or insert is test-fired to confirm draft.

Why old clay tiles crack

Clay flue tiles are durable but brittle. A hot fire after a cold start, a small chimney fire burning off creosote, or water getting in through a cracked crown and sitting in the joints can all split a tile. Monsoon rain coming down an uncapped flue, from June 15 to September 30, also washes mortar out of the tile joints over the years.

A cracked tile lets heat reach the brick and the wood framing around the chimney, and lets exhaust seep into the masonry. That is why a damaged tile flue should not be used until it is repaired or relined.

Liners and gas conversions

Most of the liners we install go in with a gas insert. Owners of older brick fireplaces often switch to gas because gas is exempt on Maricopa County No Burn Days, which are declared mostly in the cooler months and often around the holidays, exactly when people want a fire. A direct-vent insert usually needs a liner from the insert up to the top. HomeGuide's 2026 range for a gas insert, installed, is $2,000 to $5,000; for converting a wood fireplace to gas overall, $1,500 to $8,000.

Gas line work to a new insert may need a permit. The City of Phoenix lists new gas piping and alterations to gas systems as permit work. We check what your city requires before the job is scheduled.

Stainless steel, the usual choice

Stainless steel liners suit most Valley jobs because they can be run down an existing flue without taking the chimney apart, and they come in sizes for both wood and gas venting. Cast-in-place liners and new clay tile exist but involve far more masonry work. We explain the options and price the one that fits your chimney.