A chimney sweeping log is a device that is burned in a fireplace to make a chimney cleaner and less prone to fires. While it is recommended to have a chimney cleaned yearly in places where a chimney is used three or more times a week during the heating season, some claim the logs can be almost as effective as a chimney cleaning. Those using a chimney sweeping log should keep some things in mind, however.
Chimneys need consistent attention to be maintained in proper working condition. When a fire is first lit, and to a lesser extent when it is burning, deposits build up inside the chimney in the form of creosote. This tar-like substance can ignite, causing a chimney fire. These hot fires can be extremely dangerous to the entire house, quickly melting the chimney and spreading to other areas.
While a chimney sweeping log is meant to save money, even the warnings on most packages say that the logs are not meant to take the place of a regular, professional inspection. Even those using a chimney sweeping log should have their chimneys inspected on a regular basis. Therefore some have openly questioned, if an inspection, and likely a professional cleaning, is going to be needed, why use the log?
To understand the answer to that question, those who manufacture the logs say there is more to a chimney sweeping log than meets the eye. For example, while the log may, indeed leave some deposits, manufacturers say the chemicals in a chimney sweeping log may leave the vast majority of the deposits inflammable. This increases safety significantly, they say.
Those using a chimney sweeping log may find there is less buildup over time as well. As the creosote is coated with the chemicals in the log, it is supposed to become very brittle. Over time, this should cause it to flake off and burn gradually or fall to the bottom of the fireplace, where it can easily be cleaned out. One company manufacturing the logs claims it can reduce the buildup in a chimney by as much as 60 percent.
While there may be some validity to the claims, many professional firefighting organizations warn that a chimney sweeping log is no substitute for a true professional cleaning. Even though a professional and chimney sweeping log may use some of the same chemical agents, there are key differences. The Washington Public Fire Educators Association notes that while it does not dispute what a chimney sweeping log can do, flaking creosote can be a hazard in itself.