Wood stove combustion is never pure, so smoke going up the chimney always contains some unburned gases and tars. If the chimney's inner surface is cool, the unburned gases and tars will condense out of the smoke onto the chimney's surface. Creosote will eventually build up.

Creosote in a chimney is dangerous because it is the fuel for a chimney fire. Chimney fires produce intense heat and sparks. The intense heat can crack the tile of a tile-lined chimney or speed decay of a prefabricated metal chimney. After holes or cracks have developed, chimney fires can cause the wood framing or roof of the house to catch on fire. To reduce this danger, chimneys should be cleaned and inspected at least once a year, and more often depending on the amount of use and burning practices.

Many people who burn wood try to increase the time between refueling by restricting the wood's air supply and/or by filling the firebox as full as possible. The end results from these practices are a cooler firebox and an increased creosote buildup.

The greatest buildup of creosote is when the fire is starting to develop or is smoldering. A good rule to follow in cutting down the chimney's creosote buildup is to get a hot fire going rapidly.

Reducing the creosote problem requires efficient stove operation along with knowledge of what type of wood to use. An easy test is to look at the smoke leaving the chimney. As the smoke's density increases, so does the creosote buildup. Reducing creosote buildup will help you burn wood more safely.

Good wood-burning practices will decrease the amount of creosote buildup in your chimney, but don't forget about cleaning the chimney. Inspect the chimney regularly, establish a cleaning schedule, and you will decrease the chance of a chimney fire.