ABOUT CHIMNEY FIRES
Every year, the CCVFC responds to multiple chimney fires right here in Colchester. Some are minor, but some are major catastrophes that can result in the tragic and unnecessary loss of life and/or property. With home heating costs rising tremendously, many residents will turn to less expensive wood heat in the winter. This means the potential for chimney fires will rise. The following information is intended to help you understand chimney fires and prepare your wood heating system for safe operation.
What causes a chimney fire?
Your woodstove is designed to safely contain a wood-fueled fire. Your chimney is designed to expel the byproducts of combustion--the substances given off by burning the wood. As these substances go up your chimney, creosote is formed through condensation caused by the relatively cooler flue. Creosote is usually black in color, and can be dry and flaky, tar-like, drippy or sticky, or even form a hard and shiny coating on the inside of your chimney. Regardless of its appearance, ALL forms of creosote are highly combustible! If enough builds up in your chimney, it is only a matter of time before you could have a destructive chimney fire.
Restricting air flow, burning “green” wood and cooler flue temperatures all contribute to a faster buildup of creosote.
As creosote burns, it will often expand tremendously (remember those fireworks ‘snake’ pellets that are small cubes until you light them-then they expand to many times their original size? That’s creosote!), and can partially or completely block your chimney-which in turn can fill your home with heat and deadly smoke.
How does a chimney fire damage my chimney?
If you have a pre-fabricated metal chimney, a chimney fire can cause buckling or warping at the inner liner joints. If this occurs, the chimney should no longer be used and should be replaced.
Masonry chimneys can have very high temperatures (2000 Degrees Farenheit!) during a chimney fire. These extreme temperatures can cause the mortar to fail, chimney liners to collapse and cause damage to the outer masonry materials. If tiles crack and/or masonry is displaced, this creates a pathway for the fire to spread to the wood structure in your home. Because of the high temperatures, enough heat can even conduct through a perfectly good chimney and ignite your home during a chimney fire!
How do I prevent a chimney fire?
The good news: Chimney fires are preventable. Here are a few tips to help you get through this heating season safely:
- NEVER burn your Christmas tree, cardboard, wrapping paper or trash. These items can spark a chimney fire as hot pieces of burning material travel up your flue.
- Don’t burn wet wood! Using dry, seasoned hardwood is best, as burning wet wood can lower flue temperatures, causing more creosote to condense on the inside of your chimney.
- Get your chimney cleaned & inspected before you burn every year. I cannot emphasize enough how important this is. Yes, it costs money, but it could save your house from burning down; it might even save your life!
- Build smaller, hotter fires that burn more completely, thereby reducing creosote buildup in your flue.
- Check your smoke detectors. Change the batteries, and make sure they are in good working order. Replace older detectors. Carbon Monoxide detectors are a must-have as well!
What to do if you have a chimney fire:
- Get everyone out of the house to a safe distance.
- Call the fire department immediately!
- If you can do so with no risk to yourself (remember, your home can be replaced-you can’t!):
ABC/Dry Chemical powder extinguisher
-Close the doors on the woodstove
-Close all air inlets to the woodstove
- Once you’ve had a chimney fire, do not use your woodstove again until you have had an inspection and cleaning done. Any chimney fire damage and subsequent repair is usually covered by your homeowners insurance policy, so give them a call!
This article was written by John Meyers, CCVFC, as a Public Safety Announcement and may be reproduced for non-profit public safety and educational purposes only.
Fore more information regarding chimney fires, please visit the Chimney Safety Institute of America.