University of Missouri Extension

G1735, Reviewed December 1993

Cleaning Stovepipes and Chimneys

David E. Baker
Department of Agricultural Engineering

With ever-increasing fuel costs, heating with wood has again become very popular with Missourians. But this increased use of wood-heating equipment brings with it the need for constant, careful attention to assure the safe and efficient use of this heat source. One area often ignored is the special care needed for the chimney.

Chimney fires

Creosote accumulation is the main reason for cleaning a chimney. If the buildup of creosote on the chimney's inside surface ignites, a chimney fire results. Chimneys need cleaning to prevent this buildup and thus reduce the possibility of a chimney fire.

The extremely high temperatures (up to 2,000 degrees Fahrenheit) of a chimney fire can damage the chimney. The heat can warp metal chimneys and crack the tile liner on masonry chimneys.

Never use water on an extremely hot chimney fire, since this quick cooling can also crack the tile liner or warp the metal chimney. After the fire has been extinguished, have the chimney checked for warped metal or a cracked tile liner.

If you don't repair cracks or holes in the flue, the next chimney fire could be even more dangerous. Even during normal use, the sparks generated by the fire in the stove could go through the cracks or holes into the attic or the framework surrounding the chimney. This could cause a serious house fire, resulting in loss of property and possibly loss of life.

To avoid this tragedy, you need to establish a cleaning schedule that will free your chimney of creosote buildup. This schedule can range from once every couple of weeks to no less than once a year. How often you clean the chimney depends on the amount you use your stove, the type of wood you burn, the type of wood-burning unit you have and the way you operate the unit.

If, however, a chimney fire occurs, follow these steps to reduce your losses:

Cleaning the flue

You can either clean the chimney yourself or hire a professional chimney sweep. Chimney sweeps who will do a thorough and professional job are available in many communities. Watching a sweep clean your chimney would not only be educational, but would also help you decide whether or not to tackle the job yourself next time.

Before deciding to clean your chimney yourself, consider your physical condition. Cleaning a chimney can be strenuous work. Pulling a chimney brush the height of the chimney can strain the back and other muscles. Make sure you are up to the job before starting.

If you do decide to clean your chimney yourself, make these preparations before beginning the actual cleaning job.

Now you are ready to start cleaning the chimney. The best time to clean is when the chimney is still warm, since creosote comes off a warm surface easier than a cooler surface. But make sure the fire is completely out.

The following are some of the more common methods for cleaning chimneys:

Clean up time

Now that the chimney is clean, it's time to go back inside the house to clean up the soot and creosote that has fallen to the bottom of the chimney. If you are cleaning a fireplace, carefully remove the seal from the fireplace opening and sweep the soot and creosote into containers. Make sure you sweep out the accumulation on the smoke shelf above the damper, too. It is better to use an industrial or shop vacuum cleaner for this job. After this initial cleanup, use a wire brush to scrape off the deposits from the inside of the fireplace and from around the smoke shelf. Tidy up the area, and you're finished.

Remember, chimney fires are very dangerous and are a major cause of wood-burning related house fires. The more you do to keep your chimney in good working condition, the safer and more efficient your wood-burning operation will be.

 

G1735 Cleaning Stovepipes and Chimneys | University of Missouri Extension

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