Regular maintenance and cleaning of your fireplace takes a little time but it will pay off in the long run allowing your fireplace to run at it’s maximum efficiency safely. First things first, an annual inspection of your fireplace/chimney is recommended by all local municipalities no matter where you live. Even if you have taken good care of your fireplace, animals can build nests, leaves can fall inside the chimney, vapors could accumulate and things you cannot see can also happen causing a possibly bad situation, maybe even hazardous.
Check out the Chimney Institute of America, it is a non-profit educational organization existing to provide chimney and venting safety resources to you, the homeowner.
“The primary job of a chimney service professional is to aid in the prevention of fires related to fireplaces, wood stoves, gas, oil and coal heating systems and the chimneys that serve them. Chimney sweeps install, clean and maintain these systems, evaluate their performance, prescribe changes to improve their performance, and educate the consumer about their safe and efficient operation.”
If you decide to clean your chimney yourself, the first task is to clean the creosote, the source of most chimney fires, out of the chimney. Running the proper-sized chimney brush up and down from the top of the chimney is the best method. First, seal off the fireplace opening in the room.
Moisture is the main culprit in masonry chimney failures. Brick, concrete and mortar seem hard, but they are permeable to water. While you are up on the roof cleaning out the creosote, inspect the cement chimney crown. Brush away any loose pieces. If it is still basically intact and just has some cracks and pits, coat it with a elastomer crown repair material. You can select a brush- or trowel-on material. It stays flexible and seals better than mortar.
A deteriorated/loose flashing can be another way for water to enter the chimney. Installing new flashing is best, but most homeowners find it much easier to use a flexible flashing repair compound. It is brushed on over the flashing. Next, inspect the mortar joints. Remove any loose mortar and fill it with mortar or a concrete-colored elastomer sealant. Finally, seal the entire chimney exterior with a water repellent. Be sure to select one which allows the masonry to breathe so moisture does not get trapped.
There's no “one-size-fits-all” rule for how often to clean your chimney or what to use when you do it. It is always best to contact your local fire inspectors office and ask what they recommend before deciding on anything where your families safety is concerned.
(information obtained for this article are merely recommendations by homeowners, not something that should be attempted without careful consideration.)