A chimney fire occurs when a build-up of soot and creosote ignites inside the venting system of a fireplace or wood stove. Wood-burning chimneys should be cleaned when a quarter inch or more of soot is present. Build-up can be more rapid in a wood stove than in a fireplace. In a wood stove vent, dangerous build-up may occur in less than a month or may take much longer, depending on burn habits, fuel and other variables. New wood stove users should inspect their systems during the first season to learn their rate of soot build-up and determine cleaning frequency. Newer certified “clean-burning” stoves generate much less creosote than older non-certified stoves. Fireplaces usually do not need to be cleaned as often as wood-stove. Cleaning frequency is again determined by the type and amount of wood being burned.
