How Much Does a Chimney Liner Cost?

What the price is built from

A liner job is priced from the appliance up to the cap. These are the factors that move it the most, roughly in order of how often they change the total.

• Length: a taller chimney needs more liner and more time on the roof
• Diameter and shape: set by the appliance's venting instructions; larger liners cost more
• Material and alloy: aluminum, stainless steel in different alloys, or a cast-in-place lining
• Insulation: often required by the liner maker for wood-burning and exterior chimneys
• Access: roof pitch, height, slate or tile roofing, and how equipment reaches the top
• Prep work: sweeping, removing broken tile, or enlarging the flue so the liner fits

How the material choice shifts the job

Aluminum is the lower-cost material, but it only serves certain listed gas appliances, so it is not really an alternative for wood or oil. Stainless steel comes in different alloys, and the liner maker lists which fuels each one is made for; a liner for an oil boiler or a wood stove has to be the alloy listed for that fuel, not whichever is cheapest. Flexible stainless follows bends in the flue. Rigid stainless suits straight flues and is often used where a liner has to be cleaned hard and often.

A cast-in-place lining is a different kind of job. It takes more labor and material than many metal liners and needs curing time, and it is usually chosen where the old flue itself needs sealing and strengthening, not just a smaller size.

Insulation adds material and time. It comes as a blanket wrapped around the liner before it goes down, or as an insulating mix poured around it. Whether it is required depends on the fuel, the liner's listing and the chimney's construction, so it should be stated on the estimate rather than left as an extra.

The old flue decides a lot

Sometimes a new liner slides into a clean, straight flue with room to spare. Often it does not. Heavy creosote or oil scale may have to be cleaned out first, glazed creosote may need a separate removal treatment, and broken or shifted tiles may have to come out so the liner can pass. Where the old clay is too tight for a liner of the right size plus its insulation, the tile is broken out along the flue, which can be a substantial part of the work.

Offsets change the plan too. A flexible liner can follow a moderate jog in the flue; a rigid one cannot. If anything unusual turns up inside, it should be in the price from the start rather than found halfway through.

All of this is found at the inspection, which is why a price given over the phone, without anyone looking down the flue, can only ever be a rough guess.

Access, height and city conditions

Getting to the top of the chimney is a real cost driver in this region. A steep slate roof on a New Jersey or Main Line Philadelphia house needs care and protection under every ladder and walk board. A four-story brownstone without a roof hatch may need a lift or scaffolding. On a block of attached rowhouses, the chimney often sits on the party wall, and reaching it can mean working from a neighbour's roof, which takes their permission and some scheduling.

City streets add their own details, from where the truck and equipment can stand to how long a long liner coil can sit at the curb. Permit rules for relining or changing an appliance vary by town, so check with your local building department; where a permit is needed, it belongs in the estimate.

Parts beyond the liner

Liner material is often talked about by the foot, but it is one line on the bill. A complete installation has several other parts, and an estimate that leaves them out does not show what the job will cost.

• The tee or connector at the bottom where the appliance pipe joins
• A cap for the bottom of the tee, so debris can be cleaned out
• The top plate that seals the liner to the crown
• A cap with a screen over the liner
• Insulation, where the liner's listing or the chimney calls for it
• For fireplaces, work on the smoke chamber or damper area so the liner connects properly

Comparing two estimates fairly

Prices for the same chimney can differ a lot, and usually the scope differs more than the price. Lay the estimates side by side and check that each names the liner material and alloy, the diameter and how it was worked out, whether insulation is included, the top and bottom parts, and any cleaning, glaze removal or tile removal. If one is far lower, look for what is missing before looking at the total.

Ask too how the size was chosen. A liner sized from the appliance's instructions and the venting tables is a different product from one picked because it fits the flue.

The cost of putting it off

Waiting rarely makes a liner job smaller. A boiler that keeps venting into a cracked or oversized flue keeps soaking the masonry with acidic condensate, and over a few winters that can turn a liner job into a liner plus rebuilt brick above the roof and a new crown. Tile that falls to the base can also narrow the flue, and a flue that cannot vent properly can push exhaust, including carbon monoxide, back into the house. A CO alarm by the boiler, plus one on every bedroom floor, is worth having whatever the chimney's condition.

Timing affects the schedule more than the price. Late summer and early fall are when everyone remembers the heating system, so planning a reline in spring or summer gives more choice of dates. Work can go ahead in winter, but ice, snow and high wind on the roof can push a day back.

Repairs worth doing on the same visit

A liner is often part of a bigger fix. If the crown is cracked or the flashing leaks, it makes sense to handle it while the crew is already on the roof, since water is often what ruined the old flue in the first place. Caps on neighbouring flues in the same stack, a cleanout door that no longer closes, or a rusted connector pipe at the boiler are common add-ons. Each should be listed as its own item, so you can see what the liner costs and what the repairs cost.

We inspect the flue top to bottom, measure it, note the appliance and its venting instructions, and look at the roof and access. You then get a free written estimate with upfront pricing that names every part of the job before anything is ordered.