Stainless steel chimney relining for Bourbonnais and Kankakee County homes

By Jacob Dove, founder of Friendship Chimney Sweep · 29 years in the trade

What a liner does

The liner is the passage the smoke actually travels through. Its job is to contain heat and combustion gases so they cannot reach the brick, the mortar or the wood framing around the chimney, and to carry them out at the right speed so the appliance drafts properly. Clay tile liners were the standard for most of the last century and do that job well until they crack. Once a tile is cracked, heat and gases leak into the chimney structure, and a chimney fire can ignite the framing. That is why NFPA 211 treats a damaged liner as a chimney that must not be used until it is repaired or relined.

Stainless steel liner grades

We install stainless liners listed to UL 1777, the safety standard for chimney liners. Two alloys cover almost every job:

• 316Ti for wood-burning fireplaces, inserts and stoves. It handles the high heat and the corrosive creosote of solid fuel.
• AL29-4C for high-efficiency gas furnaces and water heaters, whose cool, acidic exhaust condenses inside the flue and will corrode ordinary stainless.

Liners come flexible or rigid. Flexible liners snake through offsets and are what most Bourbonnais chimneys need. Rigid sections are used in straight flues where a smoother wall gives slightly better draft. We choose based on the chimney, not on what is on the truck.

Sizing

An oversized liner drafts poorly and builds creosote; an undersized one starves the fire and smokes into the room. For a fireplace the liner cross-section is generally sized to one-tenth or one-twelfth of the fireplace opening depending on chimney height. For an insert, stove or gas appliance, the manufacturer’s manual specifies the flue diameter and we follow it. We measure before we order.

Insulation

A liner should be insulated with a ceramic blanket wrap or poured insulation mix unless the manufacturer’s listing says otherwise. Insulation keeps the flue gases hot so they rise instead of condensing, which means less creosote and better draft, and it is required for the UL 1777 zero-clearance listing when the chimney has combustibles too close. In an exterior chimney on the north side of a house, which is most of the chimneys in our area, insulation is the difference between a liner that stays clean and one that glazes up in two seasons.

How we reline

1. Level 2 camera inspection to confirm the liner is needed and to map the flue, the offsets and the tile condition.
2. Measure the flue, choose alloy, diameter and flexible or rigid, and confirm the appliance’s requirements.
3. Sweep the old flue. Cracked tiles that are in the way are broken out from above.
4. Assemble the liner on the ground with insulation, then lower it from the top with a nose cone, connecting to the appliance or a new smoke chamber adapter at the bottom.
5. Seal the bottom connection, install a top plate and a new cap, and finish the crown around the new termination.
6. Test the draft and camera-check the installed liner. Your report includes the liner listing and warranty paperwork.

Relining for gas appliances

A furnace or water heater vented into an old unlined or oversized masonry flue is a carbon monoxide risk. The cool exhaust condenses, the acid eats the mortar, and eventually the flue clogs with fallen debris or the tile collapses. Lining these flues with AL29-4C is one of the most important jobs we do in older Kankakee and Bradley homes, and it is often required when a new high-efficiency furnace goes in.

Liner pricing depends on height, diameter, alloy and insulation. Typical starting points are on our pricing page, and the exact number comes with the inspection.