The flue lining is arguably the most important safety component in a chimney. Prior to about the 1930s, a lining was not required in U.S. chimneys. The extreme danger of operating a fireplace or wood stove without a flue lining in the chimney was discovered, however; and at least one expert referred to building a chimney without a flue as downright criminal.
Even when a chimney is built with a flue, there are times when the chimney lining is improperly built and therefore unsafe. Over time, chimney linings deteriorate. If there is so much as a tiny crack in a flue, combustible parts of the home are exposed, placing the structure at a high risk for a very dangerous fire. The real scoop on flue linings is that they are essential safety features which need to be inspected annually, cleaned as needed by a professional chimney technician, and replaced when damaged.
There is one more danger attached to flues and that is failing to properly fit a flue to an appliance. One of the potential results of an ill-fitting flue is that carbon monoxide poisoning could be released into the home. Carbon monoxide is also known as the “silent killer” because it is tasteless, odorless, and invisible.
Clay Chimney Liners
Clay tiles are by far the most popular lining material to use when a chimney is being built because the tiles are both inexpensive and highly durable. Properly built and maintained clay tile linings can last as many as 50 years or more. When it’s time to replace the liner, however, clay is not a cost-effective material to choose. Other options for chimney liner replacement are usually favored because it is very labor intensive to tear out clay tiles before installing new ones. In fact, it is usually necessary to tear out the chimney wall every few feet, to replace clay tiles.
A cast-in-place liner is a flue constructed with poured cement. This process of lining a chimney with cement is less invasive, less laborious, and can be less expensive than rebuilding a clay tile liner. Both types of liners last for about 50 years. Cast-in-place liners are suitable for any and all types of fuel-burning and can stand up to the harmful effects of condensation, acids, and heat.
Metal Flue Liners
Stainless steel flue liners are popular with many fire-protection experts and installers. Less labor is required to install metal liners, and they are readily available in all sizes and types. Aluminum liners are not as expensive as stainless steel liners, but they are only suitable for certain medium-efficiency gas appliances. Steel liners, on the other hand, are suitable for all types of fuel-burning, including gas, oil, and firewood, providing excellent protection. It is important, however, to install insulation in addition to a metal liner.
The decision regarding what type of flue liner to use or whether to try and repair damaged liners is best made according to individual circumstances. Rigid metal flue pipes are available but cannot be used in all chimneys; they should be used with straight chimneys that have no bends or offsets. Flexible liners are available in a wide range of diameters, from 2” to 10”.
Contact our professionals to schedule a chimney inspection and learn what the scoop is on current condition of the flue lining in your chimney.
Northeastern Chimney, Inc.
formerly Nayaug Chimney Services, LLC
37 Cody Street, West Hartford, CT 06110