What is a chimney liner?

A chimney liner is a tube or layer of material installed inside the flue of a chimney to safely vent combustion gases, smoke, and moisture from fireplaces, wood stoves, furnaces, and water heaters. The liner creates a controlled pathway for these gases to exit the home while protecting the surrounding masonry and framing from heat damage, corrosion, and dangerous backdrafting.

Three main liner types are used in Connecticut homes and businesses:

• Clay tile liners are fired ceramic sections stacked inside the flue. They are durable and work well for wood-burning fireplaces but can crack if exposed to rapid temperature changes or corrosive flue gases from oil or gas heating.
• Stainless steel liners are seamless metal tubes that resist corrosion and withstand high temperatures. They are flexible enough to navigate bends and offsets in existing chimneys and suit oil, gas, and wood fuels.
• Cast-in-place liners are poured directly inside the flue and harden to form a monolithic protective layer. This method seals cracks in damaged masonry and accommodates irregular flue shapes.

A sound liner prevents toxic gases like carbon monoxide from seeping into living spaces and stops water from entering the chimney structure. Whether a chimney needs a new liner, repair, or replacement depends on its age, condition, and the fuel source of the appliance it serves. Connecticut chimney contractors assess liner integrity during annual inspections.