There are many benefits to installing a chimney liner inside your flue, and chimney liners are available in a variety of materials. Depending on the application, chimney liners can be made from poured cement, clay tiles, rigid metal pipe, or flexible metal pipe.
For many applications, a flexible chimney liner is the best choice for balancing cost, durability, and ease of installation.
Every chimney should have a properly installed, high-quality liner to keep combustion gases safely contained inside the flue until they are vented outside the building. If your chimney was built before clay tile liners became common, or if your existing liner is damaged and needs replacement, the benefits of a flexible chimney liner may make it an excellent choice for your chimney system.
If your chimney liner is maintained in good condition and correctly sized for the appliance it serves, it can contribute to the safe operation of your chimney system and improve your home’s energy efficiency. Installing a new chimney liner is often necessary when adding a woodstove insert, boiler, furnace, or other fuel-burning appliance, and a replacement liner is essential if the existing liner develops cracks, leaks, or other damage.
Among the different chimney liner materials available, flexible stainless steel liners are often among the easiest to install in many applications. Cement and clay tile liners generally require experienced professionals and can involve significant labor costs, which may outweigh the savings from using less expensive materials. A flexible steel liner should also be installed by a qualified professional, but its flexibility allows installation to be completed more quickly and efficiently, helping to reduce labor costs.
In some situations, a chimney liner made from rigid metal pipe may be the most appropriate option. However, assembling multiple pipe sections and creating properly sealed joints requires precise fabrication and installation. Additional fittings may also be necessary when the chimney flue includes offsets or bends rather than running straight from the top of the chimney to the appliance connection.
For chimneys with offset or curved flues, a flexible chimney liner can be guided through the bends and corners inside the flue with considerably less installation work. Flexible liners are typically installed as one continuous section, resulting in fewer joints where combustion gases could potentially leak.
Flexible chimney liners are available in a range of diameters and alloy types to accommodate many different applications without extensive custom fabrication. The corrugated construction of flexible liner material can also help reduce the accumulation of creosote and ash inside the flue by allowing deposits to loosen as the liner expands and contracts during heating and cooling cycles.
Your choice of chimney liner should be based primarily on the manufacturer’s requirements for the specific fuel-burning appliance you plan to vent through your existing chimney. The liner should also meet applicable industry standards and local requirements for materials and installation. In many situations, the combination of durability, flexibility, and easier installation makes a flexible chimney liner an excellent choice for the application.