Chimney liners for wood stoves: types, installation, cost

What a chimney liner does

A chimney liner is the inner channel that carries smoke and gases from your stove to the outside. In a conventional masonry chimney, that channel is a clay tile liner surrounded by brick, block or stone.¹ When a stainless steel liner is added to an existing chimney, Natural Resources Canada (NRCan) describes three jobs it does: it reduces the flue to match the size of the appliance collar, it isolates flue gas from the masonry, and it holds heat, which produces a stronger draft.¹

That last point matters more than most people expect. NRCan explains that bigger is not better for a chimney: flue gas moves faster and has less time to cool in a smaller flue, and the flue should be the same size as the appliance flue collar.¹ A warm, fast-moving draft means smoke goes up the chimney instead of into the room, and less creosote, the combustible residue left by unburned wood gases, condenses on the walls.⁴

When a wood stove needs a chimney liner

NRCan is clear that it is not safe to simply hook up a wood stove to an existing chimney and start heating with it.¹ These are the situations where a liner, or a new one, is needed.

Fireplace inserts and hearth-mount stoves

This is the most common reason people search for a chimney liner. NRCan states that one rule applies to all fireplace inserts: a full stainless steel liner must run from the insert flue collar to the top of the chimney, and municipal installation codes require it to be properly sized.¹ Hearth-mount stoves, which sit in front of or partly inside a fireplace, must also be vented through a liner that is continuous from the flue collar to the top.¹

In the past, installers sometimes used only a short length of stainless liner to connect the flue collar to the base of the fireplace chimney. NRCan reports that experience showed inserts did not work properly that way, even with a direct connection.¹ If you are weighing an insert, our guide on whether wood stove fireplace inserts are worth it covers the bigger picture, and the liner should be part of the budget from day one.

Unlined or damaged masonry chimneys

A masonry chimney must have a liner of clay tiles, firebrick or stainless steel to be suitable for a wood-burning appliance. Some old, unlined chimneys can be upgraded by installing a certified stainless steel liner.

Stainless steel vs clay chimney liners

The choice usually depends on whether the chimney is being built or repaired. Clay tile is the standard in a conventional masonry chimney.¹ Stainless steel is the common choice for relining, for inserts and hearth mounts, and some certified brands are also approved for new chimney construction.¹

How chimney liner installation works

In Canada, wood-burning installations follow CSA B365, the installation code for solid-fuel-burning appliances and equipment.¹ Your installer will know which edition applies where you live. A proper job generally follows these steps:

1. Inspection. A qualified chimney sweep should inspect the existing masonry chimney before the appliance goes in.¹ They look for cracks, stains on the outer bricks and missing liner pieces.¹
2. Cleaning. The fireplace and chimney must be cleaned thoroughly so no combustible deposits remain.¹
3. Sizing. The liner is sized to the appliance flue collar, not to the old chimney.¹
4. Installing the full length. For inserts and hearth mounts, the liner runs continuously from the flue collar to the top of the chimney.¹ Fitting it can mean altering the masonry fireplace.

What a chimney liner costs

We have not found an official source for chimney liner installation prices in Canada or the US, so this article does not quote dollar figures. Published numbers online come mostly from retailers and contractors. CSIA says prices vary from region to region, and that repair costs depend on the extent of damage, the difficulty of the job and the materials used.³

In practice, ask each installer to explain how these affect their price:

• The height of the chimney and how easy the roof is to reach
• Rigid or flexible stainless steel, or another liner type
• The insulation method
• Any masonry work, such as altering the fireplace or repairing the crown
• Cleaning and inspection before the work starts

Get at least two written quotes from certified installers and compare the scope line by line. A full liner can also save money later: NRCan notes that it lets the chimney be cleaned from the top, so the insert does not have to be pulled out for cleaning, a costly procedure that can damage the hearth.¹

Looking after a lined chimney

A new liner does not end maintenance. The EPA and fire officials recommend a professional inspection and cleaning every year.⁴ Quebec advises sweeping at least once a year, and spring sweeping gives you time to make repairs before winter.⁶ Sweeping logs and chemical additives never replace a professional sweep.⁶ Between visits, look at the outside of the chimney for rust or corrosion.⁶

The stove matters too. EPA-certified stoves burn more efficiently than older non-certified models and leave less creosote in the chimney.⁴ For what a sweep checks and how often to book one, read chimney cleaning: how often, cost and what a sweep does.

Questions