Do I need a Chimney Liner?
While your chimney is a complex system with a detailed anatomy, there is one component every homeowner should understand; the chimney liner. The liner is actually a very crucial part of every chimney, but what exactly is a chimney liner & what does it do? Here is a quick lesson on the internal workings of your chimney. The flue is the passageway inside a chimney where smoke, gases, and combustion products are carried up and out of your home. The chimney liner is the material on the inside of the flue that keeps all of the combustible materials safely contained as they make their way up the chimney. Since the liner is such an important aspect of your chimney, getting an annual cleaning and inspection by a certified chimney sweep will help ensure that your liner is in good working condition and safe to use.
During your annual inspection, a chimney sweep tech may advise that a new liner be installed. This could happen for a few reasons. If your chimney was designed before the 1940’s, chances are you don’t even have a chimney liner, and the technician will recommend that you have one installed. If the chimney liner you currently have was installed incorrectly or does not fit properly, it is advisable to have a new one retrofitted into your chimney. If your currently liner is in poor shape and deteriorating or defective in any way, it’s best to remove the liner and have a new one installed. A chimney without a liner is a safety hazard and can be the cause of house fires and property damage, so having a properly functioning liner is of utmost importance.
There are 3 types of chimney liners currently available; clay tile liners, cast-in-place liners, and metal liners. Each type of liner will equally provide adequate protection for your chimney, but there are circumstances where a certain material may be a better choice. Here’s a detailed looked into chimney liner materials and which is best for your home and hearth.
Clay Tile Liners
Clay tile liners have been around since the early 1900s and are often found in older homes. These are also an extremely popular option in today’s time for good reason. Clay tiles are able to withstand extremely high temperatures without damaging or hindering the performance of the liner. The combustible products creating from burning fires can be pretty corrosive and clay tiles are able to retain their integrity well against these materials as they pass through the flue. Clay liners are also extremely popular because they are relatively inexpensive and last for about 50 years.
There are some drawbacks that you will also need to consider regarding clay tile liners. Even though the materials to create clay liners are inexpensive, the installation process is long and can be somewhat costly if they are not built into the chimney during the initial construction of the home. Replacing a clay tile liner is an even more difficult task. Old tiles need to be chipped out of the chimney from your roof and require the use of special chimney sweep tools. On some occasions, chimney walls and masonry must be broken down in order to access old clay tiles. The installation process is tedious, especially for flues that are not perfectly straight. The shape of clay tiles can also trap air and affect the draft in your chimney since the interior is not perfectly round. Due to the difficulty of this job, it is recommended not to take this on as a home repair job but call in a chimney sweep professional instead.
Cast-in-Place liners are great options for chimneys that are in poor shape or need a new flue. This style of liner will reinforce the existing chimney while providing a durable and effective liner for combustible to escape. Much like clay tile liners, cast-in-place liners are extremely durable since they are also not affected by heat or corrosive gases & smoke coming from the fireplace. Another great benefit of cast-in-place liners is that they allow fires to burn cleaner and the chimney to acquire less creosote buildup as a result. Since it works as good chimney insulation and creates higher temperatures within the chimney, a cast-in-place liner is a great option for people who are looking for good heat efficiency. Just like clay tile liners, this style can last up to 50 years if well taken care of.
While the installation process for a cast-in-place liner is less invasive than a clay tile liner, it still requires some difficult procedures. There are a few different ways that this type of liner can be installed, and this can also vary between chimney sweep contractors. One way involves inflating a long rubber bladder in the chimney, then pumping a special mortar mix around the bladder. Once the mortar dries, the rubber bladder is removed leaving behind a perfectly smooth, round surface. Another installation method involves a bell shaped form that vibrates as it is being removed up the chimney and at the same time that mortar is being poured into the chimney. The mortar sets around the bell as it is pulled out of the chimney leaving a round opening down the entire chimney. Ask your local chimney sweep professional about additional preferred methods for this style liner to get a better idea of what method is used in your area.
Metal Flue Liner
Metal flue liners come in a number of different shapes and materials. Generally, stainless steel alloy is the most popular choice. You’ll find that metal flue liners come in two different forms; flexible or rigid. A chimney sweep contractor will be able to choose the best type for the shape of your chimney and usage, but here’s a little about both styles. Rigid liners are perfect for chimneys that are completely straight and contain do bends or off-sets. Flexible liners are a better option for chimneys that may have settled or developed a crooked flue over the years. Both liners will give you sufficient protection, but a flexible liner does have an additional benefit. Flexible liners actually develop less creosote and soot buildup because they expand and contract as the temperature in the chimney changes. This will knock off any creosote and soot buildup as it moves in and out which keeps your chimney in a better and safer condition. Unfortunately, metal flue liners do experience corrosion more often than a clay tile or cast-in-place liner. This can be addressed though by using the proper type of alloy based on what type of fuel is being burned. Using insulation with the metal flue liner will help keep the temperature in the chimney higher which can help get rid of condensation which can cause corrosion to the liner. The relatively simple installation and the flexibility to utilize them in all types and styles of chimneys make them a popular choice in today’s day and age.
Each type of liner has its advantages and disadvantages. Contact your local certified chimney sweep and talk to their professionals to help decide which liner will work best in your chimney.
Chimney Solutions, Inc.
1155 McFarland 400 Drive, Alpharetta GA 30004
Office 770-255-1300 / Toll Free 877-697-9337