how to prevent one.
Chimney fires occur when heavy amounts
of creosote build up on the flue liner walls and ignite. This results in a fire
up in the chimney flue rather than down in the fire box or wood stove where it
is supposed to be. Creosote is a by product of burning wood and
coal in fireplaces and wood stoves. It is commonly found inside chimney flues
when the wood or coal burns incompletely, producing soot and tarry smoke.
Often times a homeowner will close down the damper trying to make the wood last
longer or last through the night. This is the wrong thing to do. When the damper
is closed down, the fire is starved of oxygen and the fire cools down. If the
fire is allowed to burn hot and fast, the smoke and combustion byproducts are
carried up the flue and vented to the outside with very little of it attaching
to the flue walls. When the damper is closed down the fire burns cooler and the
resulting combustion byproducts are cooler. This cooler exhaust travels up the
flue slower and cools even more before it reaches the top. As it cools off the
moisture will tend to condensate and allow the creosote and ash to stick to the
sides of the flue liner. Over time the buildup of creosote and ash can become
quite thick. When conditions are right, the creosote is ignited and burn very
hot up in the flue. Most fireplaces have clay tiles for the flue liner.
Clay tiles generally crack when a chimney fire occurs due to the intense heat.
Once cracked, the flue tiles no longer serve their intended purpose of
containing the smoke and heat and must be replaced. Re-lining a chimney can be
very expensive. It is much cheaper to use proper burning techniques and
have the chimney cleaned by a qualified Chimney Sweeps each year. As the old
saying goes- "An ounce of prevention is worth a pound of
cure"
Best practices for preventing flue fires:
Leave the damper fully open and allow the fire to burn hot
Only burn dry seasoned wood. Green wood burns cooler and accelerate the build up of
creosote
Have your chimney cleaned at least once per year by a qualified chimney professional.
If you burn your fireplace daily all winter, you may need it cleaned twice per season.
Chimney fires can be very dangerous to your family. They often occur at night while you
are asleep and if undetected, the home can be fully involved before you know it- possibly
trapping you or a family member in the home
For more information call Chimney Sweeps at 423-398-1632 or email at [email protected]