Caring for fireplaces and wood-burning stoves.

• Position: Safety - Brief Article

With the chill of winter approaching, the thought of warming up by a crackling, toasty fire is enticing. Before lighting that match, though, experts advise ensuring that your fireplace or wood-burning stove is operating properly in order to maintain the safety of family members and your home. "Any wood-burning device should be checked periodically and cleaned according to usage," warns Michael Kuhn, director of home inspections for HouseMaster, a national home inspection company.

The most important consideration when it comes to fire is safety. Homeowners should conduct their own yearly inspection to ensure that their units perform properly. Before using your fireplace for the first time each season, Kuhn suggests checking the visible areas of the chimney for any blockages or creosote (a highly flammable, gummy deposit) build-up on the interior of the chimney walls and the surface of the flue. "Any deposit over one-quarter-inch-thick is a potential fire hazard and should be cleaned professionally."

Creosote residue accumulates on relatively cool chimney linings and, when ignited, causes an extremely dangerous fire. To prevent creosote build-up, homeowners should maintain a moderate fire hot enough to prevent a cool flue liner, but not hot enough to ignite creosote already formed. "Burning unseasoned or green wood creates a `cooler' fire, which increases the chance of the creosote build-up." To lessen this problem, Kuhn suggests using aged, seasoned wood, which will burn hotter.

Even if there is no creosote noticeable to the homeowner, the fireplace should be professionally inspected and cleaned once every year if used regularly or periodically, or if there is any hint of a problem. "Sometimes a homeowner will only inspect the chimney from inside the home," he explains, "but creosote can also form close to the top of the chimney, near the roof, where the colder temperature cools fireplace gases." Since 90% of chimney fires are caused by creosote build-up, an inspection of the chimney from both ends, whether done by the homeowner or a professional, is recommended.

If a gas unit is used inside the fireplace, either as an alternative to wood burning or as an igniter, special precautions should be taken. Most safety regulations require that gas-burning units be connected to a fireplace with a functional and permanently open flue to allow for the exhaust of combustion products and natural gas. "I also advise homeowners to check the...