Skip to main content
🕗 Mon–Sat 7:00 AM – 7:00 PM · Serving Mokena & 15 nearby towns📞 Call (708) 500-6096

What Creosote Is and Why It Causes Chimney Fires (New Lenox, IL)

By /

Creosote is the tar-like residue that wood smoke leaves on the inside of your flue, and it is the number-one cause of chimney fires. For New Lenox homeowners who enjoy a fire on cold nights, understanding how creosote forms — and how to keep it in check — is the difference between a cozy season and a dangerous one.

How creosote builds up

As wood burns, it releases smoke full of unburned particles and moisture. As that smoke cools on its way up the flue, it condenses and sticks to the walls in layers. Slow, smoldering fires and unseasoned (wet) wood produce far more of it than hot, bright fires with dry wood. Over a season those layers can go from a dusty film to a thick, glazed crust.

Why it causes chimney fires

Creosote is highly flammable. When a flue gets hot enough — during an especially hot fire, for example — that buildup can ignite, producing an intense, roaring chimney fire that can crack the flue and spread to the home. Regular sweeping removes the fuel before it can catch.

Keeping creosote down in New Lenox

Burn only seasoned hardwood, give fires enough air to burn hot and clean, and never burn trash or treated wood. Then have the flue swept once a year. We serve homeowners across New Lenox with thorough chimney sweeping and a Level 1 safety check on every visit.

Frequently Asked Questions

What exactly is creosote?
It is the flammable, tar-like residue that wood smoke deposits inside your flue as it cools. It builds up in layers over time and is the leading cause of chimney fires.
What makes creosote build up faster?
Burning wet or unseasoned wood, running slow smoldering fires, and a cool or oversized flue all increase creosote. Hot fires with dry, seasoned wood produce much less.
Can I remove creosote myself?
Light surface soot is one thing, but glazed or heavy creosote needs professional tools and technique to remove safely and completely. Attempting it yourself often spreads soot through the home and misses the worst areas.
How do I know if I have a lot of it?
Shine a light up the flue with the damper open. Buildup thicker than about an eighth of an inch, or a shiny black glaze, means it is time to stop burning and schedule a sweep.
What does a chimney fire sound like?
Often a loud roaring or crackling, sometimes with dense smoke or a strong hot smell. If you suspect one, get everyone out and call 911, then have the chimney inspected before using it again.
How often should New Lenox homeowners sweep?
Once a year if you burn wood, before the heating season, and more often if you burn heavily or use unseasoned wood.
Does an annual inspection help?
Yes. An inspection catches creosote and other problems early, before they become a fire risk or an expensive repair.
How do I schedule a sweep in New Lenox?
Call or text (708) 500-6096 or book online. We serve New Lenox and the surrounding south suburbs with up-front pricing.

Keep this winter’s fires safe. Call (708) 500-6096 or book your sweep online.

By Mark Vega, Owner & Lead Chimney Technician · Published September 15, 2026

Our chimney and venting work follows the NFPA 211 standard for chimney, fireplace, and vent safety.
📞 Call Now
Scroll to Top