Cleaning (or “sweeping”) a chimney is a messy job, but it ought to be done regularly to remove built-up creosote and soot, which can catch fire or obstruct the air flowing through the chimney.
Restricted airflow can cause a fireplace to operate poorly and sometimes cause soot and ash to blow back into the house.
It’s often wise to hire a chimney sweep for this job, but you can do it yourself if it’s possible for you to work safely on the roof and you can reach the top of the chimney. You’ll need:
• A steel chimney-sweeping brush
• A rope the length of the flue and the chimney
• A water-filled plastic jug to serve as a weight for the brush
• A heavy-duty vacuum cleaner
Here’s how to sweep a chimney:
Tape plastic sheeting across the mouth of your fireplace. Use old sheets or dropcloths to protect nearby rugs and furnishings. Plan to wear a dust mask, gloves, and goggles to protect yourself from the dust, ash, and soot.
Carefully climb onto the roof and, if the chimney has a cap or spark catcher attached to the top, remove it. Tie the water-filled jug to the bottom end of the chimney brush and the long rope to the top end.
Lower the weight and brush down into the chimney, all the way to the bottom, and then pull it back up. Pass it through several times until it comes up relatively free of debris. Let the dust settle, and then return back inside and vacuum out the soot and debris that has fallen into the fireplace.
If your chimney isn’t equipped with a damper, costly heated air is being drawn out through the chimney every day. Have a mason install a damper inside the chimney, or mount a special chimney cap on top that includes a damper.
Inspect your chimney at the beginning of each heating season. Shine a flashlight up inside and look for obstructions such as leaves or birds’ nests; also check for soot buildup.
Burning highly resinous wood such as pine will cause flammable creosote (a saplike material) to build up on the inner walls of the chimney. Also look for any missing or cracked flue tiles.
From the outside or on the roof, look for crumbling mortar, loose or missing bricks, or flashing that has pulled away from the roof and the chimney.
If you live in earthquake country, check your chimney for cracks after noticeable temblors. Some cracks are harmless, but others may need to be repaired to prevent them from becoming a fire hazard.
For repair information, see Chimney Repairs.