Do you need a chimney liner?

What a liner does

A liner contains the combustion gases, protects the chimney walls and the house framing from heat and moisture, and gives the exhaust a path of the right size. A listed liner should be installed following its manufacturer's instructions and be correctly sized for the appliance.

When a liner comes up

Signs you might look into one

• Pieces of clay tile or crumbled mortar in the firebox or on the cleanout shelf.
• Smoke or odor with the fireplace out of use.
• A fire that draws badly after a new appliance was fitted.
• Staining on the chimney walls inside the house.
• A recommendation after an inspection, with photos or video you can see.

Alternatives to a full liner

Some damaged clay flues can be repaired by resurfacing the inside, which is a different approach from inserting a new sleeve. Whether it fits depends on the flue condition. See HeatShield flue repair for one such method.

How to decide

• Start with an inspection that includes the inside of the flue. See inspection levels.
• Ask for the finding in images or in writing.
• Ask whether repair or relining is proposed, and why.
• Ask what material, size and installation instructions apply.
• Compare options in clay tile versus stainless steel liners.

Common misconceptions

"All old chimneys need a liner." A sound flue that suits its use may not.

"A bigger liner is better." A liner has to suit the appliance. See liner sizing basics.

"A liner fixes a leaking crown." It does not. Water entering at the top still needs the top repaired.