From the outside, most chimneys look about the same: usually they’re constructed of brick and mortar and extend in a square shape from a home’s roof and into the air. All serve the basic function of venting a fireplace or heating stove, but the inside of a chimney is a different story.
Through the 1940s, there were few regulations regarding how chimneys were built. Typically, they included nothing more than the bricks they were made with. Over time, the intense heat from a fireplace begins to erode even the strongest bricks, causing cracks and deterioration that allows heat and sparks to come into contact with surrounding walls.
And we all know what happens then.
Fortunately, chimneys in homes built since 1950 or so include what’s known as a chimney liner, a protective inner sleeve that is not as apt as bricks to break down and can provide many years of safe fireplace or wood stove use. If your chimney doesn’t have a liner, or if it does and it’s more than 40 to 50 years old, you owe it to yourself to consult with a chimney professional and have a thorough inspection performed.
There are several materials used in chimney liners today. These liners can be added to a chimney without a liner or used as replacements for chimneys with liners that are compromised. Let’s look at the most popular choices.
Cast-in-place chimney liners
This style of liner is a good choice when you have a chimney with damaged masonry. These durable liners provide good protection from high heat and offer superior insulation, allowing for the cleaner burning of fire and less buildup of creosote. As the name implies, cast-in-place liners are poured as a mold to create a round opening for smoke and exhaust.
Though cast-in-place chimney liners offer high durability, the cost can also be high and prohibitive to some homeowners.
Clay tile chimney liners
For this kind of liner, clay tiles are stacked and the joints are sealed with protective mortar. They maintain efficiency even with extreme heat going through them and should last about 50 years. The tiles are not expensive, but the installation process usually is – and it should only be performed by a professional who is experienced in clay tile liners. Another drawback is that the square shape of the tiles can negatively affect the draft within the chimney.
Metal chimney liners
Many homeowners today go with metal chimney liners. They come in both rigid and flexible varieties to perfectly fit any chimney. The company that performs the installation will recommend the specific type of metal that will be most efficient based on the type of fuel your fireplace runs on. Metal liners can be insulated, to keep hot temperatures within the chimney and protect against condensation.
In most cases, metal chimney liners are the best choice for economy of cost and speed and simplicity of installation.
If you’d like to know more about chimney liners and how they allow chimneys to operate with the utmost safety, the experienced staff at Marsh’s Stoves & Fireplaces of Toronto will be happy to help you. Stop in at our showroom at 3322 Dundas Street West. You can also reach us by phone at (416) 762-4582.