If you have an older home chances are that your chimney is going to be unlined. Over the years the interior of the chimney bricks and mortar deteriorates because of the cooling of exhaust gases produced by heating equipment. As the exhaust gas cools it creates condensation and can ultimately deteriorate the chimney to a point where exhaust gases escape the chimney. There is hope though, you can install a retrofit chimney liner.

There are two main ways to install a chimney liner. One is to install a cement liner by using an inflated balloon that is inflated while down the length of the chimney. This creates a tube or void in the center of the chimney. Mortar material is then poured around the exterior of this balloon. When the material has dried and set the balloon is removed and a solid liner then exists around the interior perimeter of the chimney.

The second method is to use a flexible metal liner which is basically a tube of stainless steel that is fed from the top to the bottom of the chimney. This type of liner can be used for boilers and furnaces but can not be used for wood burning fireplaces or wood stoves. Professional installation is recommended but if your ambitious you may want to perform the job yourself. A metal scaffold has to be installed around the chimney and working high off the ground is required. Do not attempt the installation if you are not able to aquire and erect a proper scaffold system.

The chimney must be professionally cleaned before the liner can be installed. Any missing and chipped mortar should be replaced. It is a good time to tuck point the chimney because you or a chimney professional already has the scaffold erected. It will also be less expensive if you incorporate a tuck pointing with the other work being performed.

The flexible stainless steel chimney liner is installed as follows. You will need the help of another person while performing this installation. Drop a long length of medium thickness line down the length of the chimney. Attach the lower end of the flexible chimney liner to the opposite end of the weighted line. This will allow an assistant to gently pull and guide the new liner down through the length of the chimney. While your assistant guides the chimney liner down you are simultaneously feeding the flexible chimney liner down the chimney.

After the chimney liner is completely down the chimney the end has to be connected to a plate which is provided by the manufacturer of the metal liner. The plate will be situated over the hole in the chimney and the smoke pipe from the heating appliance will connect up to the plate. This will allow the heating appliance to vent exhaust gas up through the new metal chimney liner. Seal all gaps where the plate meets the chimney with refractory mortar to tightly secure the plate.

The metal chimney cover can now be installed at the chimney top. The end of the flexible liner will attach to the bottom of this cover so the exhaust gases can escape. The last step is to install the metal chimney hat at the flue outlet at the very top of the chimney. The chimney hat is secured by four screws positioned around the exterior of the chimney hat.

The installation of a new chimney liner is challenging but it is possible for a motivated individual to take on the project. The use of a retrofit cement liner should be left to a professional chimney mason or sweep. Before you attempt the installation a professional chimney sweep should be called in to make sure the structure of the chimney is stable and can accommodate a chimney liner.