Chilly weather is here and a warm fireplace will feel good! However, your fireplace should be inspected and cleaned each year before using it. Chimney sweeps are experienced and typically do a good job for a modest price, but if you as a homeowner want to inspect and clean your fireplace yourself, it is not a difficult job, just a dirty one! A professional chimney sweep should be called if there is significant soot and creosote build-up noted during your inspection of the fireplace. (Wearing a hat and goggles are a good idea. A respirator or high quality dust mask is also recommended.) If you choose to hire a chimney sweep, look for someone that is certified and insured and will provide an upfront cost estimate.
1. First, check the firebox for cracks and loose joints. Check for damage (spalling and cracking) in the mortar and bricks if it is a masonry fireplace. (Refractory cement can be used for minor repairs.)
2. The damper should be opened and closed to insure that it moves freely and closes securely. The metal should not have cracks or damaged areas.
3. Next, the flue should be inspected using a high-powered light. A metal flue liner should have its joints aligned and be clean. If the flue liner is tile or masonry, there should not be any cracks. Look for any obstructions such as birds’ or squirrels’ nests, leaves, and debris and clean, as necessary. Look for soot and creosote build-up next. A good way to determine if your chimney needs cleaning is to run the point of your fireplace poker along the inside of the chimney liner. If there is 1/8” or more of buildup (the thickness of a nickel), the flue needs cleaning. If the soot has a matte black finish and the scratch is no more than a nickel thickness, it’s a DIY job. However, if the buildup is deeper or has a shiny or tarlike appearance, there may be heavy creosote buildup. In this case, a professional chimney sweep is recommended.
Creosote build-up in a flue may catch fire. A small hot spot of creosote can smolder for hours after the fire in the fireplace has gone out. If the flue fails in a fire, the wood framing and insulation in the house can ignite. Creosote forms as a result of gases that have not fully combusted, and it condenses on the inside of the chimney and remains until removed. Burning green or unseasoned allows creosote build-up to occur faster. Creosote is formed in the upper parts of the chimney when the warm vapors contact the cold outside air. Creosote is a black or brown residue that clings to the inner surfaces of the flue liner. Creosote can be dry or sticky and hard and glassy or flaky. Therefore, it is critical that all creosote, as well as soot, is removed every time the fireplace is cleaned. Most chimney fires start in the smoke chamber/smoke shelf area, so it’s the most important area to clean
To clean the chimney yourself, a good quality chimney-cleaning brush is needed. These large brushes have plastic or stiff wire bristles and are attached to an extendable pole. Dropcloths should be laid around the hearth area and a heavy duty shop vacuum is needed to clean up the debris loosened. First, the chimney opening should be brushed thoroughly, followed by extending the pole section by section and cleaning each area of the flue thoroughly. Brush the firebox thoroughly and finish by vacuuming the damper area, smoke, shelf, and firebox.
If mostly green (wet) logs are burned, the chimney should be cleaned or inspected every 50 burns. Green wood doesn’t burn cleanly and sends a lot of unburned particles (smoke) up the chimney, where they build up as creosote and soot. Dry hardwood, such as oak, burns hotter and cleaner. With dry hardwood, the chimney should be cleaned or inspected every 70 burns.