Company Blog

Creosote F.A.Q.

One of the leading causes of chimney fires, according to the Chimney Safety Institute of America (CSIA), creosote build-up is a dangerous fact of life when you have a wood-burning fireplace or stove. Removing creosote deposits from your chimney walls is a big part of your annual chimney sweeping, and this maintenance can save you and your family’s life since creosote building up on your chimney walls puts you at risk of a chimney fire.

It isn't possible to clean 100% of the creosote in your chimney. However, you need regular maintenance to keep the level low.

It isn’t possible to clean 100% of the creosote in your chimney. However, you need regular maintenance to keep the level low.

The CSIA-certified chimney sweeps at Blue Sky Chimney Sweeps clean your chimney thoroughly to remove any creosote sticking to your chimney walls when performing their chimney sweeps. We at Blue Sky Chimney Sweeps would like to answer some of the most frequently asked questions we receive about creosote to inform you about this fire hazard.

What exactly is creosote and how does it get in my chimney?  Occurring naturally, creosote is the resulting residue of the condensation that occurs when the by-products of combustion (smoke, gases, vapors, unburned wood particles, tar fog, and other assorted minerals) leave the fireplace or wood stove and exit the cooler upper chimney. This residue sticks behind on the chimney walls.

What does creosote look like? Varying in appearance, creosote can be either black or brown, and it takes different forms: sticky and tar-like, flat and shiny, and crusty and flaky. No matter what it looks like, creosote is highly combustible in every form.

How does creosote build-up start chimney fires? If the build-up is large enough and your internal chimney flue temperature gets hot enough, a chimney fire could ignite, thanks to the highly combustible makeup of creosote.

Are there conditions that encourage the development of creosote deposits? Yes, certain things to help creosote to build up more quickly: restricted air flow, burning unseasoned wood, and cooler than normal chimney temperatures.

What can I do to change these conditions? To keep air flowing properly and without restrictions, open the glass fireplace doors when burning a fire, and always be sure your damper is wide open when burning a fire. You want to be sure you have enough air flowing into your fireplace to move heated smoke up the chimney quickly because the longer the smoke stays in the flue, the more likely creosote will form. When using a wood stove, do not close down the stove damper or air inlets too soon or too much. Always use seasoned firewood because burning unseasoned wood keeps the smoke cooler because the fire spends so much time burning off the excess water in the wood cells. Also, when using a wood stove, never overload the firebox with wood in an attempt to get a longer burn time because this also adds to creosote development.

What is the best way to prevent the accumulation of large creosote deposits? As the CSIA says, “clean chimneys don’t catch fire.” Having your chimney swept annually by a CSIA-certified company like Blue Sky Chimney Sweeps is the best possible prevention of creosote building up large enough to ignite a chimney fire. Our chimney sweeps are well experienced with creosote removal, and can rid your chimney walls of all creosote deposits.

If you have more questions about creosote and chimney fires, contact Blue Sky Chimney Sweeps today. We will be happy to schedule an appointment for your annual chimney cleaning to give yourself peace of mind regarding a possible chimney fire.

Watch Out for Creosote!

The Different Stages of Creosote Buildup in a Chimney

Until they own a home with a chimney, many people have no idea what creosote is. Creosote is actually a combination of chemicals that are left behind after treated woods and coals are burned in the fireplace. There are three different stages of creosote buildup and each has different consequences. One of the top priorities of a chimney sweep during your annual cleaning and inspection is to eliminate creosote buildup.

There are a few reasons that creosote cannot be allowed to accumulate inside of the chimney. One is that the substance is extremely flammable and will increase the risk of a dangerous chimney fire. In addition, there are health risks associated with creosote. It can irritate the eyes or skin if someone comes into contact with it and it also causes respiratory issues after prolonged exposure.

Creosote buildup is a fire danger, but it can also cause respiratory problems.

Creosote buildup is a fire danger, but it can also cause respiratory problems.

In the first stage, creosote is fairly easy to remove because it is flaky and dusty. At this stage, it can usually just be brushed out of the chimney with a brush. However, in this stage, it is very easy for the creosote to catch a stray spark and start a chimney fire. Just because it can be removed easily does not mean that it is not still a serious problem.

If the creosote problem is not taken care of in the first stage, it will quickly move on to the next stage. At this point, the creosote becomes crunchy and tar like and is much more difficult to remove. Once it reaches the second stage, a simple brushing will not do it. It will be necessary for someone to get into the chimney and scrape the creosote from the walls.

Once the homeowner has let their creosote problem advance, it becomes particularly dangerous. In the third stage, creosote becomes glazed and can be extremely difficult to remove. At this point, it behaves like candle wax and will actually melt and spread throughout the chimney during a fire. Once it reaches this stage, the entire family is at risk as a result of the creosote.

As soon as there is a suspicion that creosote is building up in the chimney, it is a good idea to call a chimney sweep. A chimney sweep will have the training and tools necessary to clean up the creosote properly. If an inexperienced homeowner tries to do it on their own, they may not fix the problem entirely. Worse, they could expose themselves and their families to the creosote, putting them all at serious risk.

Creosote buildup is a serious issue and should not be taken lightly by homeowners. If their family is exposed to the substance, they may become injured or ill. Additionally, the creosote can start a chimney fire that will spread throughout the home.  It is important to remember that these risks exist even in the early stages and to have a chimney sweep clean the creosote as quickly as possible.