How a Dirty Chimney Can Start a House Fire

Do you use your fireplace throughout the winters? If the answer is yes, like so many other homeowners, then you need to have your chimney cleaned. It’s not something you’d think about, perhaps because chimney sweeping sounds like it’s a thing of the past, but it’s one of the most important tasks you can do to keep your home safe.

According to the Chimney Safety Institute of America (CSIA), there are signs you should be aware of that can indicate the start of a chimney fire:

  • Noises: a chimney fire will sound like loud cracking or a popping noise
  • Smoke: these fires produce thick, dense smoke
  • Smell: you’ll notice a hot smell, intense to the senses

These fires burn explosively, meaning they’re loud and noticeable to anyone passing by your house. Fire and smoke will erupt form the top of the chimney. For those on the inside, homeowners report hearing a deep rumbling sound, like that of a freight train or an airplane.

Combustion Byproducts Make a Chimney Dirty

Chimneys are the channels in our homes used to deliver dangerous byproducts of combustion to the outside, far away from our living spaces. Combustion occurs when you burn wood, so when you’re enjoying that wood-burning fireplace all winter, you can expect some natural buildup of these byproducts to linger on the interior of your chimney. This residue is called creosote.

Creosote is something you’ve seen plenty of times, even if you didn’t know what you were looking at. It’s the black or brown residue that coats the interior of your firebox and chimney. It’s tar-like and can be sticky and drippy, or when hardened—shiny. No matter what it looks like, all of its forms are extremely combustible.

You don’t want to have a lot of creosote buildup on your chimney because it can result in a chimney fire. A chimney fire can occur when the internal flue temperature reaches a high point in combination with the creosote residue along the chimney and fireplace’s walls.

According to the CSIA, here are a few factors that can cause a dirty chimney—AKA creosote buildup—which can lead to dangerous chimney fires:

  • Chimney temperatures that are cooler than average
  • Burning unseasoned wood: try to burn wood that’s seasoned, meaning it’s been dried for at least six months and contains no more than 20% of moisture. You can use a special tool like a wood moisture meter, which is available at your local hardware store or online, to detect how much moisture is in your firewood.
  • Restricted air supply: avoid closing the glass doors in front of the fireplace if you have them, which can greatly restrict the oxygen supply while burning a fire. Your damper also should be opened wide enough before you begin the burn. This allows the air to move the heated smoke up the chimney swiftly. The longer smoke lingers in the flue, the more likely creosote will begin to form. This period of time is called “residence time” and you want to minimize this as much as possible to prevent buildup and subsequently chimney fires.

Modern home with chimney.

How to Prevent Fires & a Dirty Chimney

It’s easy to stop fires from happening—as easy as it is to keep your chimney clean. All you have to do is schedule an annual chimney cleaning and inspection with your local chimney sweeping company.

There are three levels of chimney inspections:

Level 1: this bottom tier of inspection is typically the most cost effective. This inspection is an examination of the readily accessible parts of the chimney exterior and interior.

Level 2: the most common form of inspection performed. The Level 2 is a safety inspection of the fireplace system with a specifically designed camera that has a 360-degree viewing ability and is manipulated to examine the entire length of the fireplace flue liner.

Level 3: the most expensive inspection includes the same services as a Level 1 and Level 2 with the addition of a partial chimney tear-down to inspect critical damages. This inspection is only recommended if the above inspections are not able to be properly completed.

For the average homeowner, a chimney cleaning and inspection is done annually. A good guideline to follow is to have your chimney cleaned once a year or when the buildup has reached 1/16” of an inch.

Other preventative measures to keep your dirty chimney clean and to stop house and chimney fires is the simple use of a chimney cap. A cap on the crown around the opening of the flue will keep debris and animals out. The cap also prevents escaped smoke from reentering and billowing back inside of your living spaces. Additionally, a chimney cap will assist in protecting the chimney from corroding throughout its lifetime.

Choosing a Trustworthy Chimney Cleaning Service

You want to be able to rely on the people taking care of your chimney needs to get the job done right, in a timely manner and provide you with excellent service all around.

Choosing the best chimney cleaning service begins and ends with Vertical Chimney Care. We’ve been serving the Chicagoland area for over 30 years with the best chimney cleaning and repair services.

We’ve dedicated ourselves to making sure your home is safer and cleaner after we’ve completed every project. Get started on your next chimney cleaning or other chimney related, Contact us today!

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