As the nights get cooler, the more we look forward to the warmth and beauty of a wood-burning stove or fireplace. However, chimneys used with wood-burning stoves, fireplaces, and fireplace inserts are potential fire hazards. Most chimney fires are ignited by the creosote, which is a black tar-like substance that builds up inside the chimney with normal use. Some homeowners may not even be aware that such a chimney fire has even happened. However, the damage caused by such an undiscovered flare-up could leave the chimney susceptible to a large, more damaging fire.
In addition, most fires involving either masonry or prefabricated metal chimneys occur because of improper installation, use, or maintenance. These are the common causes of fires:
- Improper chimney installation too close to wood framing
- Installation of thermal insulation too close to the chimney
- Improperly passing the stovepipe or chimney through a ceiling or wall, causing ignition of wood framing
- Corrosion or rusting of the inner liners of metal chimneys
- Buckling, separation of the seam, or collapsing of the inner liner of metal chimneys which can result from too hot a fire, especially in high-efficiency stoves and in fireplace inserts, or from a creosote fire
Even when a heating appliance is property installed, people with either metal or masonry chimney systems should frequently check the chimney for creosote deposits, soot build-up, or physical damage. This involves only a simple visual examination, but it should be done as often as twice a month during heavy use. If you see heavy creosote buildup, suspect a problem, or have had a chimney fire, a qualified chimney repairman or chimney “sweep” should perform a complete safety inspection.
