What Is a Chimney Liner?
A liner in a masonry chimney is defined as a “ceramic, clay, or metal conduit installed inside of a chimney, intended to contain the combustion products, direct them to the outside atmosphere, and protect the chimney walls from heat and corrosion.”
Despite the fact that building codes vary in different states and localities, flue lining installation has been recommended since early this century, with most fire codes now mandating liners.
What Do Chimney Liners Do?
The purpose of chimney liners are as follows:
1. To protect the house from heat transfer to combustible substances. In the NBS tests, unlined chimneys gave heat the leeway to move through the chimney so rapidly that the adjacent woodwork caught fire in three and a half hours.
2. To protect the masonry from the destructive byproducts of combustion. In the same NBS tests, it was found that if the flue gases were given the opportunity to penetrate through to the brick and mortar, the result potentially would be a reduction in the chimney’s usable life. The flue gases are naturally acidic and corrode the mortar joints from within the chimney. As they erode, heat transfers quicker to the nearby combustibles and toxic gases such as carbon monoxide will possibly leak into the home’s living areas.
3. To provide an appropriately-sized flue for prime appliance efficiency. Modern wood stoves and gas or oil furnaces require a correctly sized flue to perform properly. The chimney is responsible for not only allowing the products of combustion a passage out of the house, but the draft generated by the chimney also supplies the combustion air to the appliance. An incorrectly sized liner can lead to excessive creosote buildup in wood-burning stoves, and the production of carbon monoxide with conventional fuels.
Benefits of Stainless Steel Chimney Liners
1. A stainless steel chimney liner makes your home safer for a pretty small investment. If your chimney is unlined or your clay tile liner is decades old, you likely have cracked tiles or missing mortar that are possibly allowing noxious gases and smoke to enter your attic or living areas. For only a few hundred dollars, you can have a stainless steel liner installed— eliminating future leaks.
2. A stainless steel chimney liner protects your chimney from damaging combustion products. The liner gets sealed from top to bottom in order for the smoke, water, creosote, and carbon dioxide from burning fuel to be carried outside without contacting the chimney structure. Stainless steel is actually corrosion-resistant, so a liner made of stainless will last many years without leaking.
3. You can insulate a stainless steel chimney liner. The liner can be wrapped with insulation before being inserted into the flue, or the dead air space between the liner and flue can be filled with insulation after the liner has been inserted. Cement and clay tile chimney liners are typically not insulated. An insulated liner allows for less creosote condensation to enter inside the flue by keeping the combustion gases hotter all throughout and out of the chimney.
4. A stainless steel chimney liner is easier to clean than other liners. This makes it less expensive to maintain than an unlined or clay tile-lined flue. The round steel liner is easier to clean than the square or tightly rounded corners of an unlined or tile-lined flue.
5. A stainless steel liner may be more energy-efficient for your home. An insulated liner lessens the number of cold downdrafts when a fire isn’t being burned. Additionally, it improves the chimney draft since hotter gases draw better than colder gases. The complete combustion of a good draft increases energy efficiency.
6. A stainless steel liner is lesser of a hassle to install than the other types of liners. Replacing or adding a new clay tile liner inside a masonry chimney takes more work and usually more money than simply inserting a stainless steel liner inside the flue.