A sturdy chimney brush is the essential tool needed for chimney cleaning, but you should also have a breathing mask, plus plastic sheeting and duct tape for sealing your fireplace opening.
Question: I use my masonry fireplace often during winter to cut my utility bills, but the draft seems to be getting weaker. What chimney problems should I look for when I inspect it, and how can I reduce creosote buildup?
Answer: Since you have already noticed reduced draft up the chimney, schedule an appointment with a professional chimney cleaner before using the fireplace this winter. If you are lucky, basic cleaning and maintenance may be all that is required.
When my fireplace demonstrated similar draft problems, an inspection uncovered a relatively minor problem—the screen of the chimney cap was clogged with soot. Tapping the screening with a rubber mallet was enough to knock the soot loose and restore normal airflow.
If you are unlucky, there may be a dangerous buildup of creosote inside your chimney. Creosote is a black, tarlike residue created as a byproduct of burning wood. It is highly flammable and even a small buildup in your chimney puts your home at risk of a chimney fire that can spread to the house. Tens of thousands of chimney fires occur every year putting countless lives at risk and resulting in as much as $200 million in property losses.
Reduced draft may mean you have already experienced a small chimney fire. When creosote burns, it puffs up almost like plastic cooler foam, reducing air flow. The heat from a chimney fire can also cause a chimney’s tile liner to crack and fall from the masonry wall, creating an obstruction. Shining a bright light down the chimney will reveal any major blockage. Some professionals also use small cameras lowered into the chimney to conduct a more detailed examination.
If an inspection finds broken tile or puffed creosote, your chimney will definitely need a professional cleaning. If repairs are needed, get estimates from several chimney maintenance companies. In my case, one chimney company claimed to find puffed creosote and loose tiles, and estimated repairs at $7,000. Another company cleaned and inspected the chimney with a camera, but found no broken tiles. For $200 total, they also sealed the chimney crown and my fireplace has worked fine for years now.
Periodic inspections should always be left to a professional, but routine chimney cleaning—the National Fire Protection Association recommends you sweep chimneys annually—can be a do-it-yourself job if you don’t mind getting dirty.
Chimney brushes are sold at most hardware and home improvement stores, and using one is as simple as repeatedly running the brush up and down the length of the chimney to knock soot and buildup loose. Always wear a high-quality breathing mask so you do not inhale the fine dust particles, and seal the fireplace opening into the room with plastic film and duct tape. Also, put a large drop cloth on the floor in front of the hearth. No matter how well you seal it, some black dust is likely to get through. Use caution when climbing ladders and walking on roofs. I recommend you wear a
safety harness and tie yourself to the chimney to help prevent falls.
To reduce creosote buildup, use well-seasoned wood and do not choke off combustion air to extend the burn time. Wood logs can also be treated with anti-creosote sprays, and there are artificial fireplace logs that contain chemicals to reduce creosote formation in the chimney. Using these periodically can help keep your chimney clean.
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