A Clean And Safer Chimney Will Help You Relax By That Midwinter Fire

By Shannon Hicks

Keeping chimneys clean is basic maintenance for any home with a working fireplace or wood stove, yet too many times each year homeowners suffer damage — or worse — to their homes as a result of chimney fires.

Chimney fires aren’t limited to the winter months but with the recent cold snap, Newtown’s fire companies have been busy responding to calls. The town’s volunteer firefighters have also been spending time prepping for those calls with chimney fire drills.

The two key things people can do to prevent chimney fires is maintain their chimneys and use good wood.

“Depending on the usage of a fireplace or woodstove, the more use or if you use it all the time means you should have the chimney cleaned more often,” Newtown Fire Marshal Bill Halstead said last week.

Another important thing homeowners can do is use what Mr Halstead, who is also the chief of Sandy Hook Volunteer Fire & Rescue Company, calls “good” wood.

“Wood should be dry and aged before you burn it,” he said. “You don’t want to burn the green stuff. That’s the worst thing you can do.”

Hard woods including oak, hickory, ash, and maple are best.

New, fresh-cut wood creates more creosote in a chimney than aged wood does, he explained. Creosote builds up much faster when new wood is used because there is more moisture in fresh wood than in aged wood.

Creosote is the highly flammable deposit left in a chimney or stovepipe from burning wood. It usually originates as liquid but dries quickly because of the heat within the chimney. Creosote is left behind because when wood is burned for heat, the fire is not hot enough to consume all of the combustibles in the wood. The fire produces byproducts that condense on the inner walls of a chimney, and it is these condensed byproducts that form creosote.

A chimney with as little as a quarter-inch of soot contains enough creosote for a fire to ignite. A fire burning at 1,000 degrees can easily ignite creosote into a roaring chimney fire that can burn to temperatures exceeding 2,000 degrees.

Flames and flying embers from a chimney fire can easily drop onto a structure’s roof and ignite any wood framing. If the fire remains within a chimney the intense heat can cause a flue to crack or collapse, causing the interior walls of a house to burst into flames.

Outside the house clouds of black smoke and sparks will be seen exiting the top of the chimney. In severe fires, flames can extend several feet above the chimney. However, there have also been chimney fires that homeowners did not know about. Slow burning fires do not get enough air or have enough fuel to be dramatic or visible.

If, after lighting a fire in a fireplace or a woodstove, a “whoosh” is heard within the chimney chances are there’s been a fire. Chimney fires don’t always last very long, but even short fires can cause damage.

“Creosote fires are usually over in just a few minutes. That’s the roaring sound you hear,” said Mr Halstead. “But if you have a buildup, that’s when the fires burn for a longer period of time.”

Tony Cuomo, the training officer for Dodgingtown Volunteer Fire Company, led a chimney fire drill for company members on January 15 at the Dodgingtown firehouse.

“Chimney fires can be explosive, loud and dramatic enough so that you will hear them,” he said.

The “roars” of chimney fires have been described as everything from low rumbles to sounding like low-flying aircraft and even a freight train.

“When a chimney is loaded up, the creosote will also drop down on top of the shelf of the fireplace or stove, and that’s very difficult to get at,” Mr Halstead continued. Once creosote starts dropping down onto a fire element’s shelf, firefighters have to contend with putting out the fire without using so much water pressure that they destroy a chimney.

Keep the flue wide open when first starting a fire. By keeping the draft open for at least 30 minutes the heat from the fire will warm the chimney and flue. This will create a strong upward draft, which will exit smoke faster and result in less creosote buildup. The longer the smoke remains in the chimney, the more likely creosote will form.

Burning a hot fire twice a day for 15 to 30 minutes can also help reduce the amount of buildup. Temperatures should be steadily between 200 and 300 degrees. Temperature gauges for wood stoves are easily available.

“You shouldn’t throw a log on only occasionally,” he said. “A fire should be kept going. You don’t want it to be building up, then slowing down, and then raging again when a log is thrown on.”

Don’t make it a huge fire. Just steady. A smaller fire will burn hotter than a large stack of logs, and a hotter fire results in more complete combustion of the wood.

 

What To Do If There           Is A Fire

In the event of a chimney fire certainly the first thing to do is call 911 and evacuate the house.

If possible to do so safely, close the dampers and/or primary air inlet controls. This will lessen the fire’s air supply, reducing its intensity. But be careful: If the fire has built up high temperatures and there is a glass door on the front of a fireplace, the door may already be so hot that any touch could cause the glass to explode.

Move anything combustible away from the stove’s surfaces or the fireplace’s opening. During a severe chimney fire these elements can become hot enough to ignite.

Do not spray a hose down a chimney; this will only damage the chimney further.

Stay off the roof. It may already be compromised.

Another thing to remember: “DuraFlame™ logs will explode if they are exposed to water,” Mr Cuomo said.

Let the responding fire company deal with the fire. They have been trained to handle fires according to circumstances.

Newtown’s five fire companies have an arsenal of equipment available, from DryChem extinguishers and water extinguishers, tarps and blankets, metal pails and shovels to chimney chains, chimney “bombs” (which drop chemicals onto a fire), CO meters, hose lines and ladders.

A heat-measuring camera is “the best tool that we have,” Mr Cuomo said. “It makes our job so much easier. This camera tell us how deep into a chimney a fire is reaching, and it can also show us where hot spots may have taken root away from the chimney.

“If a fire has cracked a chimney and has moved into a crawl space, it may be smoldering but not visible to the naked eye,” he continued. “With these cameras we can see any place that’s hot and potentially dangerous. This means we can fully extinguish anything, before it flares up.”

Newtown Hook & Ladder Volunteer Fire Company also has one aerial truck — the only one in Newtown — that is sent out to any large structure fire in town. It also responds to chimney fires in Hook & Ladder’s district.

“With many of the new constructions, many of the peaks are averaging 30 feet or more, and that’s out of the reach of many ground ladders,” Hook & Ladder Second Assistant Chief Ray Corbo says. “Ladder 114 has a reach of 105 feet — that’s a great help to reach peaks, or to reach over cars that are in a driveway.

“The length of the ladder also allows quick set-up, and it doesn’t need to be straight up against a house,” added Mr Corbo. “It’s much easier and safer to get firefighters and equipment across a ladder on a lesser angle than it is to go up and down a ladder set flush against a building.”

 

After A Fire

After a chimney fire never use a fireplace or woodstove without first having it checked by a professional.

“Those logs you see on television, where they promise one burn will clean your chimney, they don’t work,” cautions Mr Cuomo. “They burn at a high temperature, but they don’t clean your chimney.”

Fires can crack a flue or mortar, which will allow a second fire to quickly spread outside the chimney and into a house. Fires will also crack chimney tiles and/or displace mortar, which will also provide a pathway for flames to reach a home’s wood frame.

Heat can also cause any metal around the doors of a fireplace to warp or fatigue.

If a chimney hasn’t been cleaned yet this season chances are it isn’t too late.

If a chimney has been professionally cleaned already, consider contacting a chimney sweep in a few months. Most people don’t think of woodstoves and fireplaces when it’s 90 degrees outside, but you’ll be glad you did when next winter rolls around. A chimney may not need to be cleaned every year, but it’s a good idea to at least have it inspected for build-up and heat damage.

Mr Cuomo also urges homeowners to hire professionals. Don’t skimp on cost if it means jeopardizing the safety of a home.

“Let a certified chimney sweep determine what, if anything needs to be done,” cautions Mr Cuomo. “They know what to look for.”

“Fortunately people are getting more safety conscious,” he added. “This is the season for chimney fires, and people are generally aware of what they need to do.”