The chimney liner is the part of your chimney you never see and the part that does the most to keep your house safe. It is the inner channel that carries smoke and gases up and out, and it keeps the heat of the fire away from the wood framing around the chimney. When a liner cracks, wears out or was never installed, the chimney is no longer doing its job. This guide covers what liners do, the different types, the signs you need a new one, and what the installation involves.
Looking for the service itself? See chimney relining in Dallas Fort Worth.
What a Chimney Liner Does
- Protects the house from heat. Without a sound liner, heat can pass through the masonry to nearby wood framing.
- Protects the masonry. Smoke and gases are acidic. The liner keeps them from eating away at the brick and mortar from the inside.
- Vents gases properly. A correctly sized liner helps the chimney draft well, so smoke and carbon monoxide go out instead of into the room.
The national chimney standard, NFPA 211, covers liner requirements for chimneys and venting systems.
Types of Chimney Liners
Clay tile liners
The most common liner in older masonry chimneys. Clay holds up well under normal use, but tiles can crack from a chimney fire, settling or uneven heating, and the mortar joints between tiles can fail. Damaged clay tiles are usually not repaired one by one. The flue is relined instead.
Stainless steel liners
The most common choice for relining. A stainless steel liner is run down the existing flue and connected at the top and bottom. It works with wood, gas and oil, it is the standard choice for fireplace inserts and stoves, and it can be insulated for better draft and safety.
Aluminum liners
Used only for certain gas appliances. Aluminum is not suitable for wood-burning fireplaces.
Cast-in-place liners
A cement-based mix is poured into the flue around a form. It creates a smooth, insulated liner and can add some strength to an older chimney. It is a bigger job and is chosen for specific situations.
When You Need a New Chimney Liner
- Cracked, shifted or missing flue tiles found during an inspection
- After a chimney fire, which can crack clay tiles even when the fire went out on its own
- Converting from wood to gas, or installing a gas or wood insert, where the appliance needs a correctly sized liner
- An older chimney with no liner at all
- Persistent smoke or draft problems caused by a liner that is the wrong size for the fireplace
- Pieces of tile falling into the firebox, or heavy deposits that keep coming back
Most of these can only be confirmed with a video scan of the flue, which is part of a Level 2 inspection. Read what a professional chimney inspection includes.
What Chimney Liner Installation Involves
- Inspection and measurement. The flue is scanned and measured, and the fireplace or appliance is checked to determine the right liner size and type.
- Preparation. The flue is cleaned. Damaged tiles or obstructions may need to be removed so the new liner fits.
- Installation. The liner is lowered down the flue from the roof and connected to the fireplace or appliance at the bottom. Insulation is added where called for.
- Top termination. The liner is sealed at the top, and a cap is installed to keep out rain and animals. See chimney cap installation.
- Testing. The system is checked for proper draft and connections.
How to Make Your Liner Last
- Get an inspection every year
- Clean the chimney when buildup calls for it. See chimney cleaning.
- Burn only dry, seasoned hardwood. See the best firewood for heat and safety.
- Keep a cap on the chimney to keep water out
Frequently Asked Questions
Is a chimney liner required?
Fireplaces and appliances need a properly sized, intact liner or venting system to meet the national standard. An older chimney without one, or with a damaged one, should be relined before it is used.
Can I use my fireplace with a cracked liner?
It is not safe. A cracked liner can let heat and gases reach places they should not. Stop using the fireplace until it has been inspected.
Do I need a new liner to switch to gas logs or an insert?
Often, yes. The liner must match the appliance. See gas vs. wood fireplaces and fireplace conversion.
Talk to Us About Relining Your Chimney
SafeAir Duct & Chimney is a family owned, licensed and insured business, with warranties from one to ten years on our work and Wisetack financing available. We serve Dallas, Plano, Frisco, McKinney, Allen, Richardson, Denton, Lewisville, Irving, Arlington, Grapevine and Fort Worth.
Book your chimney inspection online or call us at (214) 550-3348.
