Chimney Liner Safety

What Liners Do

• Chimney liners are a key component of chimney and fireplace safety. Typically made of stainless steel, clay or a cement-like material known as cast-in-place, chimney liners help insulate the brick and mortar structure from the heat of the smoke that is carried up the chimney. The smoke that leaves the home through the chimney also contains chemicals such as creosote that, without a liners, could attach to and damage the interior of the chimney. Creosote and other materials will slowly eat away at the structure of the chimney, and can slowly cause cracking and decay. Liners not only keep these materials away from the chimney, but also help maximize the efficiency of the chimney by making the inner chamber of the chimney smaller to minimize drafts.

Types of Liners

• To get the most out of a chimney liner, the correct one needs to be installed. For existing chimneys that don't already have a liner, metal or cast-in-place liners are usually used. These types of liners are rated as safe for both woodburning and gas fireplaces, and can be installed without damaging the existing brickwork. As these types are impervious to water, they are also well suited to improving the safety of older chimneys that may be already suffering from water damage, preventing water from leaking further into the chimney and ultimately into the fireplace. Clay liners are generally recommended for new constructions, as they are difficult to lay in place otherwise. These liners are also recommended for well-ventilated fireplaces, as they are not as temperature resistant as the other types.

Keeping Liners Safe

• Smoke deposits will build up inside the chimney liner just like they would inside an unprotected chimney, so it is crucial to regularly clean the chimney. Most chimneys will benefit from a thorough cleaning once a year, although depending on usage it may require more frequent cleaning. In addition to keeping the chimney liner clear and allowing for a clear flow of smoke, getting rid of the creosote and buildup inside the liner will also prevent odors from getting back into the home during the days there is not a fire burning. Some of the materials that build up in the chimney can be ignited by sparks, so keeping the liner free of buildup will also cut down on the risk of chimney fires.

Fire Mandates

• Chimney liners are not mandated by law in many areas, but they have been recommended by fire safety organizations such as the National Fire Protection Association for years. Each state has its own building codes when it comes to the installation or operation of a fireplace and chimney, and many of these include a properly maintained and installed chimney liner. When purchasing a new home, it is often beneficial to have not only the chimney but the liner inspected by a professional to ensure that it is up to the state's safety standards before operating the fireplace.