Wed, May 15, 2024

Clean creosote out of chimney before using fireplace

When the weather outside is frightful, you want the fire in your fireplace to be delightful. That means getting the fireplace ready for the season.

While a wood-burning fireplace should be cleaned about once a year, it also depends on how much you use it and what type of wood you burn, according to Dan Machin, owner of Top Hat Chimney Sweeps in Scotts.

“You don’t want to burn anything that hasn’t been cut, split and dried for at least nine months to a year, because it creates too much creosote,” he said.

Even following that recommendation, if you don’t clean the chimney regularly, the creosote builds up and changes form, eventually making the chimney more difficult to clean.

“First- and second-degree creosote is like a powdery soot-type material,” Machin said. “When it gets to the third-degree stage, it changes over to more of a rock-hard glaze. You can’t brush that right out with a brush. Even with the most expensive professional chimney brush, you can barely put a scratch in that stuff sometimes.”

Every time you build a fire, you have small chimney fires, said Eddie McCormack, an installer with Sackett’s Fireplace in Portage.

If you keep up with chimney maintenance, those small fires will burn themselves out. But, if you don’t clean the chimney regularly, third-degree, tar-like creosote builds up.

“If that catches fire, then you have to have the fire department out, and it could cause major damage,” McCormack said.

To help get third-degree creosote out of a chimney, Machin recommends burning a chimney-cleaning log.

“It won’t clean your chimney, but it will soften up those hard deposits,” he said. “It makes it so when you do get it brushed out, you will get a lot better results.”

Machin said he begins the chimney-cleaning process by placing a tarp in front of the fireplace. Then he checks the inside of the chimney with a flashlight to determine how dirty it is, and whether to clean it from the inside up or from the roof down. The decision, he said, often depends on ice, snow and the pitch of the roof.

For cleaning from the inside, Machin uses a machine that pulls air from the room and forces it into the fireplace, creating a big updraft.

“So, while I’m pushing my brush up and down through the chimney flue, most of the lighter stuff goes right up the chimney and out the top,” he said. “What does fall down in will hit the floor of the fireplace.”

When Machin cleans a masonry chimney, most creosote falls behind the damper. It must be removed, he said, because it’s more dangerous there than inside the chimney.

Having a professional clean a chimney also provides a safety inspection, McCormack said. Cleaners look for cracks in the liner, check the mortar joints in a masonry chimney and inspect the flashing around the chimney for leaks.

“If you have the terra cotta clay liners, I’d look for cracks in there because you can get creosote build-up in the cracks, where you can have a chimney fire past the fire-protective wall,” he said.

Rain caps and animal guards are also important to have on the top of your flue, Machin said.

“Water does a lot of damage to the inside of people’s chimneys,” he said. “Also, raccoons love to get in there. ... Right behind your damper is the perfect place for them to have babies. I get a lot of calls about that every spring.”

Gas fireplaces usually don’t require quite as much maintenance as wood-burning fireplaces — as long as they are installed and adjusted properly, Machin said.

“If it’s burning way too rich, the air/gas mixture is wrong (and) then they’ll produce a lot of soot,” he says. “But, if everything is adjusted properly, then they don’t require a lot of cleaning.”

A gas fireplace probably should be serviced about every two to three years, McCormack said. That involves a cleaning, checking the gas line and looking for cracks in the logs.

Author: Rick Eudaley, Copperfield Chimney Supply Inc.
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