If you are planning to throw a few logs into the fire place this holiday season, you may want to look before you light.

The National Fire Protection Agency says nearly half of all home-heating house fires are caused by dirty chimneys, and a majority of them happen during the winter months.

Chimney fires usually start due to a build up of creosote, a flammable reside left over from burned wood. Alexys Cellini with Mike's Mobile Chimney Service says it doesn't take long for creosote to build up inside a chimney.

"Creosote has early stages," Cellini explained. "In its early stages, it's fluffy. When it gets glazed, it's like hard candy stuck to the seat of your car."

It's recommended that chimneys be cleaned annually, but if you can't remember the last time you cleaned it, Cellini said there are two things you should look out for.

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"First thing, is there any deposits left over from the last burn," Cellini siad. "Second thing you will want to look at is your fire box. Are there any cracks?"

Cracked bricks or mortar in the fire box and the hearth is a big fire risk. The mortar and flue inside the chimney also needs to be checked from the top. 

Creosote buildup in this area can really fuel a fire.

"One thousand degrees — you don't want your chimney to get over 1,000 degrees," Cellini said. "Just because it is brick, doesn't mean it's not flammable."

It's also a good idea to inspect your chimney cap. The metal chimney caps help to prevent sparks from coming out of your chimney should there be a fire. The cap also keeps our leaves, debris and small animals.

If you are thinking about sweeping your chimney yourself make sure you have the right sized brush. Square chimney flues need square brushes, not all chimneys are the same.

"You should also make sure your damper is working properly. If not it could force smoke back into your house," Cellini said.

You can find a licensed chimney sweep near you on the Chimney Safety Institute of America's website.

Follow the conversation on Facebook with John Bartell.

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