- Creosote is the culprit responsible for most chimney fires. It is produced when wood is burned and is a byproduct of smoke that collects on the inside of the chimney. Depending on how long the creosote has been building up, it can be chalky, crusty, gummy, tar-like or glazed. Creosote that is gummy, tar-like or glazed is particularly flammable. Have your chimney cleaned before the creosote buildup reaches this point.
- Wood that is not seasoned, or thoroughly dried, contains up to 45 percent water. Wood takes up to one full year after being cut and split to dry out enough to burn well. Not only is it difficult to get a fire started in your fireplace with wet wood, but once you get it going, the wood will smoke and produce excessive creosote. According to the Chimney Safety Institute of America, have your chimney cleaned once a year if you use dry, seasoned wood and burn a fire three or more times a week during the heating season. If you use wood that is not well-seasoned, twice-a-year cleaning and inspection is recommended.
- Slow-burning, smoky fires also cause creosote to build up quickly. To reduce the amount of smoke that accumulates when you first make a fire, try building it using the top-down method. Traditionally, people have been taught to make fires with kindling at the bottom, with larger logs stacked on top. The top-down method employs the opposite procedure, with the larger logs on the bottom and kindling and wood shavings at the top. The effect of this type of burn creates a fire that heats up the flue quickly and more readily draws the smoke up the chimney. Because creosote sticks more easily to cold chimney liners, this method also helps reduce creosote buildup.
