The Signs You Have Already Had a Chimney Fire in Palos Heights
By Dan Joel, Elite Sweepers Inc.
The dramatic version, with flames above the chimney and a roaring sound, is real but it is not the common version. A great many chimney fires are slow, quiet and starved of air. They burn out on their own and nobody in the house ever knows. What they leave behind is a flue that has been through far more heat than it was built for, and that damage is still there the next time you light a fire.
What a chimney fire is
The short answer: the creosote lining the flue igniting.
Creosote is the condensed residue of wood smoke, and it is fuel. When enough of it accumulates and the flue gets hot enough, it ignites. The fire is burning the chimney’s own lining rather than anything in the firebox, which is why it can continue after the fire in the fireplace has died down, and why it can reach temperatures the structure was never designed to contain.
The evidence to look for
The short answer: puffy or honeycombed creosote, cracked tiles, a discolored or distorted cap, and debris in the firebox.
- Creosote that looks puffed up or honeycombed. Normal deposits are flat and layered. Creosote that has expanded into a spongy honeycomb texture has been burned.
- Cracked or displaced flue tiles. Rapid intense heat cracks clay tile, and pieces can shift out of alignment.
- Discolored, warped or distorted metal. A cap or metal liner that is heat-discolored or deformed has been through something.
- Pieces in the firebox. Fragments of tile or unusual amounts of debris on the smoke shelf mean something came apart above.
- Roof damage near the chimney. Scorching or damaged shingles adjacent to the crown.
- Cracks in the exterior masonry. Especially ones that appear suddenly rather than developing slowly.
Things people sometimes remember afterward: a loud cracking or rumbling sound, a dense column of smoke from the top, or an unusually strong hot smell. At the time these often get dismissed. In retrospect they are the event.
Why it matters even if nothing burned down
The short answer: the fire compromised the barrier that keeps the next fire contained.
The liner exists to keep heat and combustion gases away from masonry and from any combustible framing near the chimney. A chimney fire cracks that barrier. The next fire, an ordinary one, now has paths for heat and gas to reach places they should never reach. That is the real danger, and it is why a suspected chimney fire means the chimney should be inspected before it is used again.
What reduces the risk
The short answer: dry wood, hot clean fires, and the annual sweep.
Creosote accumulates fastest from smoldering fires burning wet wood, because cool smoke condenses on the flue walls. Seasoned wood and a properly burning fire deposit far less. The annual sweep then removes what did accumulate before it reaches a quantity that can sustain a fire. Neither alone is sufficient, and together they are the whole of the prevention. Our chimney sweeping page covers the visit, and DIY chimney maintenance covers wood and burning practice.
If you suspect one happened
The short answer: stop using the fireplace and have it inspected before the next fire.
A chimney inspection establishes whether the flue is still sound, and where it is not, our chimney relining page explains what restoring it involves. For local scheduling, see our chimney service in Palos Heights, with costs on our pricing page.
Elite Sweepers Inc is insured and bonded and works seven days a week, 7 AM to 7 PM. Call (708) 432-3977.
Chimney Fire Questions
Can a chimney fire happen without me knowing?
Yes, and it is common. A fire starved of air can burn slowly and quietly and go out on its own. The damage to the flue remains regardless of whether anyone noticed the event.
What does creosote look like after a chimney fire?
Instead of flat layered deposits, it appears puffed up with a spongy honeycombed texture. That expansion is a direct result of the creosote having burned, and it is one of the clearest indicators.
What should I do during a chimney fire?
Get everyone out of the house and call emergency services. If you can do so safely on your way out, closing the damper and any air inlets limits the air feeding it, but leaving comes first.
Can I use my fireplace after a chimney fire?
Not until it has been inspected. The liner is what keeps heat and combustion gases away from the masonry and nearby framing, and a chimney fire is very likely to have compromised it.
What causes creosote to build up quickly?
Burning wet or unseasoned wood, and running slow smoldering fires with the air restricted. Both produce cool smoke, and cool smoke condenses on the flue walls rather than leaving as vapor.
Do chimney fires damage the outside of the chimney?
They can. The rapid intense heat can crack exterior masonry, scorch nearby roofing, and warp or discolor the cap. Cracks in the masonry that appear suddenly are worth taking seriously.
Does an annual sweep prevent chimney fires?
It removes the accumulated creosote that a chimney fire needs as fuel, which is the single most effective preventive step. Combined with burning dry wood in properly burning fires, it addresses both the buildup and the cause.
Are chimney fires more likely in certain conditions?
They are most likely where creosote has been allowed to accumulate over several seasons, particularly in flues that have been used with wet wood or slow smoldering fires. A very hot fire in such a flue is a common trigger.
Published September 20, 2026