What you don’t know about your chimney can hurt you, especially if you have a gas-heating appliance that uses your masonry chimney as a venting system.
Every day, without any visible signs, the acid produced by your gas appliance may be eating away at the inside of your chimney. The resulting damage can compromise the safety of your family and the value of your home. A thorough annual inspection of your chimney, as recommended by the National Fire Protection Association and the Chimney Safety Institute of America, can alert you to potential problems before they become costly dangerous.
Why Flue Liners are Recommended and Needed
In the 1940s and 1980s masonry chimneys were tested by the National Bureau of Standards (NBS) for durability due to rising concerns about their performance and safety. These tests involved lined (using clay tiles) and unlined chimneys. Here are a few takeaways from the test:
Unlined chimneys allow heat to move through brick chimney walls very quickly. The unlined test chimney caused adjacent woodwork to catch fire after 3 ½ hours of testing. In fact, the unlined chimney performed so poorly that testing of unlined chimneys was abandoned.
Clay flue tiles were easily damaged during the testing as a result of thermal shock. All flue tile samples subjected to the heat shock test suffered damage in the form of cracking.
It was determined that if the flue gasses were allowed to penetrate to the brick and mortar, the result would be a reduction in the usable life of these components due to mortar deterioration. It is important to note that flue gasses are acidic in nature and can be quite corrosive.
At the conclusion of the testing, the researchers recommended that flue linings, and the bonding material that joins them, be capable of containing flue gasses and be designed to minimize condensation in the system.
Burns & McBride works closely with the Wertz Company to provide chimney liners for our customers.