Company Blog

Here we are again! Chimney fire “season”.

Two common causes for these fires occurring more often in late December and early January:

  • Burning of wrapping paper and old trees after Christmas.
    – Burning materials aside from the designated fuel can result in a devastating chimney fire, but in reality, even apparently safe burning can result in such an irritating inconvenience.
  • Lack of service (routine, regular chimney sweeping).
    – Our tendency for procrastination puts off annual service and then (at the last minute before the need for holiday fires) there’s no way to get an appointment and we think, “well, we really haven’t used it THAT much. It’ll probably be ok…..”


Anatomy of a Chimney Fire

Anytime wood burns, it creates by-products of combustion. These materials include smoke, soot, carbon monoxide, and creosote. The build-up of creosote is responsible for chimney fires. Creosote can be black or brown in color and flakey or slick in texture. Any combination of traits is highly flammable. With every fire in the fireplace or stove, creosote condenses along the interior of the chimney, building to increasingly dangerous levels. A stray spark or ember, from burning wrapping paper for example, can easily ignite the creosote, turning an innocent, homely fire in your fireplace into a catastrophe.

Creosote burns at 2000 degrees Fahrenheit, which is four to five times hotter than traditional wood fires. This extreme heat and the other chemical traits of creosote make these fires very difficult to extinguish quickly. Resulting damage can include melted mortar, cracked bricks, cracked flue tiles and exposed woodwork in the house. Once the woodwork catches fire, the house could very well burn to the ground, costing thousands of dollars in damage and potentially injuring or killing people inside the house.

While chimney fires often create noteworthy displays of light and explosions, they can also be secretive and slow-burning, causing damage without alerting anyone. A chimney sweep will look for signs of a chimney fire, including smoke leaking through the masonry materials, honeycomb textured creosote, discolored chimney components, and heat damaged roofing. Generally, chimney fires will leave severe damage in their wake and require extensive repairs. Sometimes it could even require entire chimney rebuilds, in order for the chimney to function safely again. These are not inexpensive repairs, so avoiding chimney fires would be a worthy goal.

Fortunately, chimney fires are, for the most part, preventable.

  • First, current fire safety standards mandate an annual chimney sweep, which involves the removal of built-up creosote from the interior of the chimney.
    – For fireplaces and stoves that experience heavy use, experts recommend more frequent sweeps, if need is indicated.
  • Second, burning the proper fuel for the fireplace or stove goes a long way toward reducing creosote buildup in the first place.
    – Burning wood that has been properly seasoned cuts down on creosote buildup, as well as burning more hardwoods than softwoods. Avoid burning freshly cut wood – like an old Christmas tree – and any kind of papers or decorations, which burn very hot and can emit sparks and embers.

For more information on preventing chimney fires, visit our Company Blog page. In the search box on that page, type “chimney fire”. That will get you started.

To schedule a routine chimney sweep in Upstate South Carolina, contact Blue Sky Chimney Sweeps.

What is a chimney fire? Why is it A BAD THING?

Short Answer:  When creosote builds up in a chimney, it can ignite and burn.  That’s a chimney fire.  That fire can reach temperatures as high as 2000° F;  and it can wreak havoc on the insides (and sometimes the outside) of a chimney.  Resulting damage can lead to premature deterioration of the structure at best.  It can endanger a home and its occupants at worst.

We can find our substantiation for this opinion in The Facts about Chimney Fires – Causes & Cures — a brochure written by the Chimney Safety Institute of America.  Most of what is in this blog will be coming directly from that information piece. Some of it is directly quoted, some of it is paraphrased.

A chimney fire can be impressive.  Chimney fires have been described as creating:

  • loud cracking and popping noise
  • a lot of dense smoke, and
  • an intense, hot smell

The Dangers of A Chimney FireChimney fires can be  noisy and dramatic enough to be seen by neighbors or passers-by.  Flames or dense smoke may shoot from the top of the chimney.  Some report a low rumbling sound that reminds them of a freight train or a low flying airplane.


However, those are only the chimney fires you know about.  Slow-burning chimney fires don’t get enough air or have fuel to be dramatic or visible.  However the temperatures they reach are very high and can cause as much damage as their more spectacular cousins.“

So…what is creosote and how can you minimize its collection in your chimney?  Let’s consult  The Facts About Chimney Fires

“The by-products of combustion (smoke, water vapor, gases, unburned wood particles, hydrocarbon volatiles, tar fog and assorted minerals) exit through a chimney during the process of using a fireplace or wood stove.

As these substances exit the fireplace or wood stove, and flow up into the relatively cooler chimney, condensation occurs. The resulting residue that sticks to the inner walls of the chimney is called creosote.  

Creosote is black or brown in appearance. It can be crusty and flaky…tar-like, drippy and sticky…or shiny and hardened.   All forms can occur in one chimney system.  Whatever form it takes, creosote is highly combustible. If it builds up in sufficient quantities – and the internal flue temperature is high enough – the result could be a chimney fire.

Certain conditions encourage or accelerate the buildup of creosote on the chimney walls

  • Restricted air supply
  • closing the glass doors
  • failing to open the damper wide enough
  • the lack of sufficient make-up air  to move heated smoke up the chimney rapidly
  • closing down the stove damper or air inlets too soon or too much.
  • unseasoned wood
  • so much energy is used initially just to drive off the water trapped in the cells of the logs– keeps the resulting smoke cooler, than if seasoned wood is used.
  • cooler than normal chimney temperatures
  • exterior chimneys
  • uninsulated chimneys”


How do you know if you’ve had a chimney fire?  For answers, let’s go back to The Facts About Chimney Fires

We’ve learned that a chimney fire can occur without anyone being aware of it.  So….

”…it’s  important to have your chimney regularly inspected by a CSIA Certified Chimney Sweep.   Here are the signs that a professional chimney sweep looks for:

  • “Puffy” or “honey combed” creosote
  • Warped metal of the damper, metal smoke chamber connector pipe or factory-built metal chimney
  • Cracked or collapsed flue tiles, or tiles with large chunks missing
  • Discolored and/or distorted rain cap
  • Heat-damaged TV antenna attached to the chimney
  • Creosote flakes and pieces found on the roof or ground
  • Roofing material damaged from hot creosote
  • Cracks in exterior masonry
  • Evidence of smoke escaping through mortar joints of masonry or tile liners”


Blue Sky Chimney Sweeps |Bless Your Hearth can help you with….

Inspections & Proper Maintenance

“Clean chimneys don’t catch fire. Make sure a CSIA Certified Chimney Sweep inspects your solid fuel venting system annually, and cleans and repairs it whenever needed. Your sweep may have other maintenance recommendations depending on how you use your fireplace or stove.”

Visit to see the complete brochure:  The Facts about Chimney Fires – Causes & Cures