That’s a good question, because a chimney liner in good working condition serves several important purposes inside your chimney. For one, it prevents carbon monoxide from getting into adjacent bricks and therefore your home. It also adds extra protection to the home’s building materials surrounding the chimney. Another purpose is to shield the chimney itself from high temperatures and caustic chemicals introduced during the burning of wood.
For these and other reasons, the lifespan of a chimney liner is an important topic. Here are general guidelines for the three most common types of chimney liners – clay tile, cast-in-place and steel.
• Clay tile: about 50 years
• Cast-in-place: also about 50 years
• High-quality stainless steel: Up to 20 years
• Lower-quality stainless steel: Possibly as few as five years
The type of chimney liner you should choose depends on several factors.
In an existing chimney. If you already have a working fireplace and chimney that has no structural damage, a stainless steel liner is going to be your best bet. These liners are fairly simple to install in existing chimneys and to connect with fireplaces or fireplace inserts.
In an existing chimney that is damaged. When structural damage to the chimney exists or there is a degenerating clay tile liner, a cast-in-place liner is the smart way to go. These liners are made with an insulated mixture similar to mortar and do a good job in patching and filling crumbling mortar joints and reinforcing the entire chimney structure.
When building a new fireplace. If you’re building from scratch, a clay tile liner is the best choice. Actually, it’s the best choice for a non-damaged existing chimney, too, but the difficulty and expense in this kind of installation make it prohibitive for most homeowners. But with a brand new chimney, it’s great because it will last a very long time and the materials used to build a clay tile liner aren’t all that expensive.
The only way to understand the exact condition of an existing chimney liner is to have it inspected by a professional chimney technician. This person may recommend a new liner in several situations.
1. There is damage to an existing clay tile liner. Cracks in the liner can let carbon monoxide and fiery sparks escape, setting the stage for poisonous gas to enter the house or the interior of the chimney to catch on fire.
2. Low flue temperatures/condensation issues. If there is no chimney liner, low temperatures in the flue will cause condensation that can lead to corrosion of the chimney structure. (Note that condensation also can be caused by sluggish air flow, which is something your service technician will check out.)
3. Fireplace conversion or insert. When you convert your existing fireplace to burn a different type of fuel, or when you install a new fireplace insert, there may be a need to put in a new type of liner. Consultation with a professional will determine whether or not this is necessary.
4. Significant damage to an existing steel liner. As noted, stainless steel liners don’t have the long lifespan of clay tile and cast-in-place liners. Over time, steel liners can warp, corrode and deteriorate, making them unsafe.
When it’s time to determine if a new chimney liner is needed, count on the professionals at Chimney Solutions of Alpharetta, GA, for the best advice, products and installation services. Call 770-255-1300 with questions or to schedule an inspection.