Chimney liners: saving your money and health

Here’s a product that’s relatively new, but also vital for a safe and comfortable home: a stainless steel chimney liner.

Flue or chimney liners protect masonry chimneys from the corrosive effects of flue gases. Flue gases are acidic and eat away the mortar joints of unlined chimneys.

While driving through your neighborhood, you may notice a few of these poking up out of the chimney tops. You can usually identify these as neighbors who have recently installed a new higher efficiency furnace.

Here’s why these are so necessary.

If a furnace is vented into a potentially oversized and unlined masonry chimney, the rapidly cooled exhaust gases are likely to condense on the inside walls of the chimney. The acidic gases will, in time, cause deterioration of the masonry chimney, causing health hazards and costly repairs.

In layman’s terms, the mortar between the bricks rots away and you can have blockages or complete chimney failure.

This steel lining protects the chimney by actually creating a new chimney within the old one. It travels from the top all the way down to the basement or area where the furnace is located. The furnace and water heater are then joined together in a T shape and attached to the chimney liner, creating a new exhaust portal that prevents damage to your existing masonry.

Chimney liners like these have been required by state code for almost 15 years. The only ones who are exempt are homes that already have steel type chimneys, called b-vent, or if your masonry chimney is not being used by either a furnace or a water heater.

A chimney liner can save you money and can save your health.

Joel Wensley is a licensed mechanical contractor in the state of Michigan, a member of the Comfort Institute, and is also the president of Mechanical Heating & Cooling in Dearborn Heights.