A Flue-Fire, also known as a Chimney-Fire is caused by the reigniting of the hazardous and extremely flammable creosote residues left in the flue due to burning of fires in the fire-box. Here is the thing, there is really no way around creosote – it is a byproduct of wood-burning and is due to the gases during the combustion (wood-burning) process, not being burned up completely – hot air rises, yes, but as those gases head up the flue, they are cooling down, and sticking to the sides of the flue system – ergo, creosote.

Creosote is combustible, so, once you have burned for a while, and not had the chimney swept or inspected, imagine what sort of hazardous material situation you have left for your chimney. When a chimney/flue fire occurs, the temperatures of these scorches can reach up to  2000°F.  Temperatures this hot are no match for your clay flue tiles, the mortar between them, or the liners that are designed to send the heat out away from your home – instead, you may very well experience a chimney/flue fire, which may be recognized by loud popping noises, dense smoke billowing out of the top of the chimney and in some instances, flames which rise or are visible out from the top of the chimney – not ideal. Those popping noises are not the noises you hear coming from the logs in the fire-box, that is simply the water or sap bubbles in the wood being heated up, expanding and cracking the wood – the popping you should be concerned about at this point is happening above your head – up in the flue.

Are your chimney/flue fires always going to reveal themselves with the above indicators? No. Do not count on it – if there is not enough air to make for flames shooting out of the flue, or loud popping noises, the temperatures of a flue-fire are not reduced. A chimney sweep and inspection is the best way to reduce and omit this from being an experience as a homeowner, with the potential of watching your house burn down due to failed stewardship of owning a home with a chimney.

There are indications that a chimney/flue fire has occurred in your chimney and we will list a few, but again, know that we offer a camera/video inspection with our sweeps, so no only will a sweep by a certified sweep professional be performed, but you will have some peace of mind knowing the condition of your chimney’s flue system before burning.

The folks over at the Chimney Safety Institute have listed a few signs that a certified professional sweep will look for that may indicate a chimney flue-fire has occurred:

  • “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

If you have recently purchased a home and have not had the chimney inspected prior to use, we would suggest it before you sit down to enjoy the fires. Otherwise, homeowners, it is recommended by the chimney sweep industry to have a chimney clean, sweep, and inspection at least once annually, if not more (depending on the amount of burning done).