There are many benefits to installing a chimney liner inside your flue and there are a variety of materials that can be used in chimney liners. Chimney liners can be made of molded cement, clay tiles, rigid metal pipes or flexible metal pipes.
For many applications, a flexible chimney liner is the best choice in terms of cost and ease of installation.
Every chimney should have a high quality liner to keep combustion gases securely contained inside the flue until they are safely vented outside the building. If your chimney was built in the days before clay tile liners were routinely built in, or if you have a chimney liner that is in need of replacement, the benefits of a flexible chimney liner might make it the right type of liner for your chimney.
If your chimney liner is kept in good condition and it is properly sized for the type of appliance it vents the gases from, it will contribute to safe operation of your chimney system and will improve your home’s energy efficiency. It is often necessary to install a new chimney liner when you install a new woodstove insert, boiler furnace or other fuel burning appliance, and a new liner is always necessary if your old liner begins to leak.
Among the various types of chimney liner materials that are available, a flexible stainless steel liner is the easiest to install in a lot of circumstances. Cement chimney liners and clay tile liners have to be put in place by experienced experts, so the labor costs involved in their installation far outstrip any savings that may come from the materials being less expensive than stainless steel. Of course, a flexible steel liner should also be installed by an expert, but it is much easier and faster to install a flexible liner, so labor costs are greatly reduced.
In some situations, a chimney liner fabricated from rigid metal piping will be the best choice. But, fitting sections of pipe together and having the joints not leak requires precision metalworking skills, and special connecting pieces have to be used if the flue is not a straight run from the top of the chimney to the connection with the fireplace, woodstove or furnace.
For chimneys with offset flues, a flexible chimney liner can be inserted so that it bends around the curves and corners inside the flue, requiring minimal labor costs for installation. A flexible chimney liner is usually installed in one continuous section, so there are fewer joints involved that may leak combustion gases.
Flexible chimney liner materials are available in a variety of diameters and alloy types to fit almost any application without the need for extensive custom fabrication. The corrugated design of the liner material tends to inhibit buildup of creosote and ash inside the flue, since the expansion and contraction of the corrugated liner breaks new deposits loose as it heats up and cools off during use.
Your choice of a chimney liner should be determined primarily by the manufacturer’s recommendations for the particular fuel burning appliance you intend to vent using your existing chimney. Your chimney liner should meet industry standards for materials and installation. In many cases, the benefits of a flexible chimney liner will make it the best choice for your particular situation.