Most Chimney Fires Are Preventable

1/22/2020 (Permalink)

Follow our tips step-by-step to prevent a destructive chimney fire from happening in your home.

Chimney fires strike more than 25,000 times each year in the U.S., and they cause more than $125 million in property damage. The most common cause of chimney fires is not having your chimney regularly cleaned and inspected. With chimneys, an ounce of prevention is truly worth a pound of cure! Protect your home and your family by keeping your chimney clean and in good working condition, always looking out for signs of trouble. This article tells you what a chimney fire is, how it starts and how to stop one from occurring in your home.

Two Types of Chimney Fires

Chimney fires come in two varieties—fast and loud or slow and quiet—but they’re both extremely destructive and can cause your home to go up in flames.

If you suddenly hear cracks and pops as loud as gunshots, followed by a deep, rumbling sound, you’ll know you have a chimney fire. Black, flaming creosote will fall into the firebox, and then, like an explosion, flames will shoot from the top of the chimney and back down into the firebox, pushing smoke into your living space. Finally, the flue may crack and flames can shoot into your walls.

?Slow-burning chimney fires never get enough air or fuel to burst into plain sight, but they can still cause similar damage to the chimney and nearby combustible parts of your home as their louder siblings do.  With a slow fire, though, you may not even know a fire occurred until your next chimney inspection.

Either way, you can’t control a chimney fire by yourself, so call 911 ASAP! Because firefighters have to fight the flames from the top of the chimney, water will flood into your house, causing water damage on top of the fire damage. You’ll need to hire a professional disaster recovery company, like SERVPRO of Bloomfield/Enfield, to completely restore both the fire and water damage to your home.

If You Have a Chimney Fire, Act Fast

If you discover a chimney fire, immediately:

• get everyone out of the house, including yourself
• call 911

Take these additional steps to help save your home only if you can do so safely:

• Place a chimney fire extinguisher or fire suppressant into the fireplace or wood stove to consume oxygen and starve the fire
• Pour sand or baking soda onto the fire in the firebox (keep a bucket of sand nearby for this purpose)
• Close the glass doors on a fireplace or the air inlets on a wood stove

While you wait for the fire department outside, try to keep the fire from spreading by hosing down your roof (not the chimney).

Once the chimney fire is completely extinguished, call a fire damage restoration expert like SERVPRO of Bloomfield/Enfield, who will remove damaged material, treat your possessions for smoke and soot contamination and restore your structure and property to pre-fire condition.

What Causes a Chimney Fire?

Fireplace and wood stove chimneys expel the substances produced when wood burns, including smoke, gases, water vapor and unburned wood particles. These by-products of combustion exit the fireplace or wood stove at high temperatures and flow up into the relatively cooler chimney, where they condense onto the chimney walls as a black or brown residue called creosote. Whatever form it takes—crusty and flaky, or sticky and drippy, or shiny and hardened—creosote is extremely combustible. When your chimney’s flue temperature gets high enough, built-up creosote can start a chimney fire, which burns at up to 2,000°F.  

The longer the smoke stays in the flue, the more creosote will form. Creosote is more likely to build up in your chimney if your fireplace or stove:

• is burning unseasoned wood
• isn’t pulling in enough air
• has cooler than normal chimney temperatures

Therefore, the key to preventing a chimney fire is to burn the right kind of fuel, set your wood-burning stove or fireplace up correctly to burn a fast, clean fire—and have your chimney and fireplace or stove cleaned and inspected regularly.

Prevent a Chimney Fire: Clean and Inspect

Every time you use your wood stove or fireplace, more oily, black, sticky creosote condenses onto the inside of your chimney. There it waits, growing thicker and putting your home and family at risk of a fire, until it is removed.

The best way to ensure that you never have a chimney fire is by cleaning and inspecting it regularly. Hire a certified chimney sweep each year before fire burning season starts, in late summer or fall. (If you haven’t done it yet this season, call today before you light another fire!) 

The chimney sweep will remove both creosote and any debris carried into your chimney by animals or wind. In addition, he or she will inspect your chimney to look for:

• creosote that’s puffy or looks like honeycomb
• metal in the damper, smoke chamber or chimney that’s been warped by heat
• cracked, damaged or collapsed flue tiles
• discolored and/or distorted chimney cap
• creosote flakes and pieces on the roof or near the house
• roofing material damaged by hot creosote
• cracks in exterior masonry
• soot deposits around mortar joints of masonry or tile liners

In addition to scheduling an annual chimney cleaning, you should make it a habit to regularly check the condition of your chimney and fireplace. Schedule another cleaning when you notice creosote that: 

• falls into the firebox during a fire
• resembles a honeycomb on the inside of the chimney
• is more than 1/4-inch thick

Schedule more frequent cleanings if you burn fires more than a couple of times a week, use lots of artificial logs or burn green or unseasoned firewood.

Prevent a Chimney Fire: Look for Signs of Trouble

Check for these indications that your chimney has been damaged. If you spot any of them, don’t light another fire until you have your fireplace and chimney inspected.

• Buckled masonry: Look for cracking or settling inside the firebox or on the fireplace’s surround or hearth, because just a tiny opening will allow sparks and high heat to reach the flammable parts of your home.
• Soot in your firebox: Crumbly black soot falling into your firebox is a sign that creosote is building up. Call for a chimney cleaning.
• Debris in your firebox: If you notice what looks like broken tiles or pot shards in your firebox, be very concerned. Especially in older homes with terra-cotta chimney liners, these pieces are a sign that the liner has already been damaged by a chimney fire. Don’t use your fireplace until it’s been inspected by a certified chimney sweep.
• More smell of smoke: If you smell more smoke than usual when you use your fireplace—or smell it outside the room where the fireplace is—extinguish the fire and call 911. Your local fire department will use heat-sensing guns or thermal imaging to check for danger and damage to your chimney.
• Changes in your walls: If heat has been escaping from cracked masonry, a damaged liner or an improperly installed prefab metal firebox, your home’s wood framing can dry, char and may ignite at a much lower temperature. If you notice pictures falling off the wall or areas of bubbling or peeling paint, call for a chimney inspection.

Prevent a Chimney Fire: Follow Best Burning Practices

Prepare your chimney and fireplace or stove so that it burns efficiently and safely, every time.

• Install a chimney cap on the crown of the flue to keep debris and critters out of your chimney. A cap will also prevent acidic rainwater from entering and corroding the chimney. 
• Insulate your chimney’s flue liner (the layer between the flue and chimney walls) to prevent flue temperatures from getting too cool. Wrap a heat-resistant insulation blanket around the liner or pour an insulation mix (such as vermiculite) into the space between the liner and flue.

When you start a fire, you want it to burn hot, fast and clean to create far less smoke, vapor and unburned wood particles, allowing little to no creosote to form in the chimney. This starts with using the right fuel.

• Always burn seasoned hardwood that has dried for at least six months and has a moisture content of 20 percent or less (you can test this with a wood moisture meter). When you burn green or unseasoned wood, energy is used initially just to evaporate the water trapped in the wood cells. This, in turn, keeps the resulting smoke cooler and more likely to condense in the chimney and form creosote.
• Use dried twigs or branches for kindling and torn or crumpled newspaper or pine cones for tinder. Avoid cardboard or glossy magazine pages that contain chemicals that can emit toxins when burned.
• Use the best fire starters for fuel, kindling and tinder, such as well-seasoned hardwood or CSIA-approved logs. Never use gasoline and kerosene to start a fire—these flammable liquids can quickly create a conflagration. And burn coal only in a coal-burning wood stove, because it can significantly raise the temperature in the flue, increasing the risk of a chimney fire.

Once you have selected the right fuel to burn cleanly, you need to build a fire that will burn hot and fast.

• Build a clean fire by using the top-down burn method, in which the largest logs are at the bottom of the fire and the smallest pieces at the top, which allows the air to mix well with the fuel. Start by placing the largest pieces of wood in the bottom of the fireplace or wood stove, with the ends at the front and back. Next, stack four to five increasingly smaller levels of wood on top of the first level, placing each layer perpendicular to the one below. Once the stack is about half the height of the firebox, add kindling (the smallest pieces of wood) in smaller and smaller pieces, then top off with wood shavings or crumpled newspaper. Light the material on the top and the fire will gradually burn its way down to the largest logs.
• Keep the damper open to allow enough air to quickly move heated smoke up the chimney. When using a wood stove, don’t close the stove damper or air inlets too much or too soon.
• Don’t overload the firebox of a wood stove in an attempt to get a longer burn time—that’ll produce more smoke and creosote.

Lastly, extinguish your fire safely and thoroughly before retiring for the night or leaving your home.

• Spread out the wood and embers, then shovel ash from the bottom of the fireplace to cover them.
• Next, completely cover the cooled wood and embers with baking soda to extinguish any remaining embers.
• After the firebox cools (for a minimum of three hours, but preferably eight), shovel the ashes into a metal container.
• Fill the metal container with water and store it outside your home and away from other flammable materials until you’re ready to discard them.

When you have suffered a fire or other disaster at your home or business, call SERVPRO of Bloomfield/Enfield at 860-216-2785

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When you have suffered a fire or other disaster at your home or business, call SERVPRO of Bloomfield/Enfield at 860-216-2785