When a fire burns, there are natural byproducts that flow up and out of your chimney system. Included among the smoke, microscopic particles, and water vapors, is soot and creosote. Like soot, creosote is a black, powdery substance that can coat your flue liner. Because creosote consists mostly of tar, it is sticky in nature and once it sticks to your flue liner, it continues to stick, building up sometimes into a dangerous fire hazard.

Early Detection and Removal

Creosote is one major reason why you should schedule chimney sweeps for your system. At a routine chimney sweep, a certified technician is able to remove creosote from your chimney’s interior using standard sweeping tools–brushes and vacuuming system. Removing creosote early not only keeps you safer during the winter, but prevents odors in the summer. When summer humidity mingles with the soot and creosote in your chimney, it can become stinky, making your home smell like a dirty barbecue grill! These odors will persist and the creosote becomes more difficult to remove as it reaches glazed creosote.

Glazed Creosote

If your chimney creosote has reached level three, or glazed creosote, it is a fire hazard. This means the creosote has been in your chimney and undergone a heating and cooling cycle for several months or years. Because of its tar content, the creosote becomes super-heated and melts into tar-like liquid, which is why it’s sometimes called tar-glazed creosote. It evaporates during high temperatures, leaving behind a hard mass of concentrated fuel that not only obstructs airflow in the flue, but is also highly flammable. It’s also harder to remove than powdery residue in the chimney.

Creosote Lowers Efficiency and Safety

Creosote buildup in the chimney means the flue liner is no longer smooth for optimal air flow. The rough, dirty walls lead to slowed airflow, which means the hot air stalls in the chimney. When the hot air stalls in the chimney, sparks can easily ignite the highly flammable glazed creosote resulting in a dangerous fire. The concentrated fuel found in a creosote-filled flue, results in a hot fire that can devastate other parts of your home, weakening supports, and burning through to your home.

What You Can Do

Creosote will always be released in your chimney, but there are things you can do to minimize the buildup and keep your family safe.

  • Burn only properly-seasoned firewood. Green wood releases more creosote into your chimney system, so it’s important to choose dry wood for your fires. Seasoned firewood also raises efficiency.
  • Schedule routine maintenance including chimney sweeps and inspections. This is the only time a certified professional will get a look at your chimney and catch weaknesses in your system. Cleaning away the creosote before it builds up is vital to prevent a creosote fire.
  • Practice good fire habits. Don’t starve your fire or let it smolder. This slows the draft that should carry residue up the chimney quickly, minimizing the buildup.

For a quick reference, check out this community handout about creosote fires and prevention. Magic Sweep also has chimney and fire experts standing by to take calls and provide professional services to keep homeowners in the Chico, CA area safe and comfortable. Schedule an appointment online or call today at 530-924-3164.