Chimney Dangers and How to Prevent Them

Falling snowflakes against pillows of smoke billowing out of chimneys are a common sight on cold days and nights while millions of families enjoy the warmth and crackling flames that a fireplace and heating stove brings during the festive winter season. While everything might seem well at first glance, there may be hidden dangers lurking in your chimney. Here are the top three chimney dangers and how to prevent them.

creosote build-up, merrimack, nhCreosote

Creosote is a chemical byproduct created during the combustion of solid and liquid fuels such as wood and gas. As it continues to accumulate in the chimney, the powdery substance hardens into a dark, tarry, and crusty material that is highly flammable. The high temperatures or a hot ember flying inside the flue can spark a chimney fire. A chimney fire can damage the interior masonry, flue liner, and other internal components. It could also spread throughout the home. Most residential fires are due to excessive creosote build-up in the chimney. Having a Certified Chimney Sweep® clean your chimney at least once annually will help prevent chimney fires.

Flue Obstruction

Flue obstructions are another chimney danger that homeowners need to prevent. It commonly occurs when small animals like birds, squirrels, and raccoons climb inside an open flue and build their nests. Falling leaves, debris, and creosote build-up can also block the vent. A flue obstruction is hazardous because it inhibits the venting of toxic fumes and exhaust causing smoke and carbon monoxide (CO) gas to back-up inside the living space. Some signs of CO poisoning include headaches, nausea, and dizziness.  Make sure to have an annual chimney inspection to minimize the risk of a flue obstruction interrupting your fireplace enjoyment. Also, install a chimney cap with a mesh screen to keep critters at bay. Periodically check that the chimney cap is secure and replace damaged or missing chimney caps as soon as possible.

flue liner, keene nhFlue Liner Cracks

The flue liner protects the masonry against the heat, flames, and toxic fumes of a fireplace or heating stove. A chimney fire, corrosion, and normal wear and tear can cause cracks to develop in the clay tiles that form the liner. While small at first, these cracks create passageways that could allow smoke and fumes to spread throughout the house, including the living space.  Moisture from water leaks or condensation can further exacerbate the problem accelerating the flue liner’s deterioration. Homeowners with clay tile liners should periodically have a video flue scan to check for flue cracks that are too small for the unaided eye to see. Also, relining the flue with stainless steel or HeatShield® will improve the chimney’s safety and efficiency.

Other Chimney Safety Tips

Here are a few safety tips to keep your family safe while enjoying your fireplace or heating stove during the winter season.

  • Only burn seasoned firewood. Wood that has been seasoned (dried) for at least six months burns more completely with less creosote, soot, and smoke, due to its lower moisture content.
  • Never toss Christmas trees, wrapping paper, or other objects into a fireplace. The chemicals in these products can create toxic fumes and may even cause an explosion.
  • Keep children and pets away from the fireplace. The firebox’s metal components will remain hot to the touch for several hours after the fire burns out.
  • Install a smoke and CO detector. Test monthly and replace batteries every six months.
  • Schedule a professional chimney inspection and cleaning at least once a year.


First Thing

John RantaJohn Ranta
17:01 22 Mar 24
They arrived on time, worked quickly and showed me the results. Prfessional throughout. jr
william greenwilliam green
23:21 14 Mar 24
Really helped me out can't say enough good things highly recommend!!!! The young man that came to my home was very knowledgeable and friendly great attitude all around answered all my questions and left me stress free best of all left no mess.🤙🏻🤙🏻
Michael Dell'OrtoMichael Dell'Orto
18:39 14 Mar 24
Jaime ConleyJaime Conley
17:13 14 Mar 24
Sarah GilliattSarah Gilliatt
01:46 13 Mar 24
A very thorough and careful job done! Thank you.
Larry CookLarry Cook
15:11 07 Mar 24
I wanted to give 5 stars but they are very busy which meant I had a good wait for both the inspection/cleaning, then for a quote on repairs and then for the repairs. Their prices seemed a little high to me but I have nothing to compare with as they were highly recommended by someone I trust and other companies had plenty of negatives reviews which kept me from getting additional quotes. I am happy with the work and they promptly returned to fix a mistake that had been made. Chris the inspector, Jennifer in the office, and Alex and his repair crew were all pleasant and took the time to answer all of my questions. Alex and his crew even took their shoes off (it was winter) before entering my house without even being asked! So if you are not in a rush and want to ensure you chimney is as safe as possible then I think you'll be happy with Black Moose.
Rebecca DeFuscoRebecca DeFusco
22:35 21 Feb 24
After a recent sweep of our chimney, it was discovered that our flue tiles were cracked. Black Moose techs were hard working, detail oriented and professional! Nice jobs guys! See you next year for my cleaning!
Karen CKaren C
14:52 14 Feb 24
Excellent I highly recommend Black Moose Chimney and Stove; Kelly and Liam are awesome, they did a great job. Extremely professional, arrived early, went through everything with a fine tooth comb ensuring pellet stove was thoroughly cleaned. They also were respectful of my home, conscientious and cleaned up after themselves. Made sure stove worked prior to leaving and told me to call promptly if anything came up afterward. Will definitely use them again.
Denise ClarkDenise Clark
16:32 31 Jan 24
We've had Black Moose clean our chimney for a number of years.But recently, we had an emergency situation at our home involving our chimney & oil furnace flue, which was caked full of soot from a malfunctioning furnace. They came & cleaned out both flues in no time, even going up on the roof with snow on it! They cleaned up after their work in the interior rooms where the oil furnace and the woodstove are located. Great work. Reasonable prices. Very nice people. You can't go wrong with Black Moose.
Joe GJoe G
18:30 24 Jan 24
Goods: The technicians know their business, very efficient in cleaning/inspection along with cleaning up after the 'dirty work'.Others: Communications could be more effective. Despite early coordination about scope of work (multiple flues within same chimney) the estimate provided did not reflect this and the final invoice was significantly more than the estimate provided.Quote for follow-on chimney relining was significantly more than that offered by other companies in the area (and far more than neighbors experienced for similar work accomplished by other companies)