How to prevent creosote buildup in chimneys?

chimney fire

Chimney fires can be extremely dangerous, causing property damage, injuries, and even death. One of the leading causes of chimney fires is creosote buildup.

Creosote is a flammable substance that forms when wood-burning stoves or fireplaces are not used correctly. When burned properly, wood produces little to no creosote.

However, if the wood is not seasoned correctly or the fire burns too low, creosote can build up on the inside of the chimney.

Depending on the type of wood being burned, the temperature, how often the fireplace is used, and the condition of the chimney, creosote can build up at a rapid pace.

Therefore, it is important to take measures to prevent creosote buildup in your chimney. In this post, we will talk about how to prevent creosote buildup in chimneys so that you can avoid the risk of a chimney fire.

Before we get into how to prevent creosote buildup, it is important to understand what creosote is and how it forms.

What is Creosote?

Creosote is a black, tarry substance that is produced when burning wood. It is made up of three things: soot, tar, and vapor.

Creosote in a Stove Pipe

Soot is the solid particles that are left behind when wood burns. Tar is a sticky, liquid substance that is also produced when wood burns. Vapor is made up of the gases that are released when wood burns. These three things combine to form creosote.

Creosote forms when the wood is burned in a stove or fireplace. When the wood burns, the soot, tar, and vapor are released.

These substances then stick to the inside of the chimney. Over time, the creosote can build up and become very thick. If the creosote is not removed, it can become a fire hazard.

Creosote buildup is a fire hazard because it is flammable. If the creosote catches fire, it can cause a chimney fire.

Why do Creosote Fires Occur?

Fireplaces and wood stoves are designed to safely confine wood-fueled fires while also providing heat to the room. The chimney’s job is to carry away combustion byproducts such as water vapor, carbon dioxide, and other gases.

As the hot combustion gases rise up the chimney, they cool down. This process can cause condensation, which leads to the formation of creosote on the inside of the chimney.

Creosote has a black or brown color and can be crusty, flaky, tar-like, or sticky. Often, all kinds coexist in the same chimney system.

Creosote, in whatever form it takes, is extremely flammable. If enough of it accumulates and catches fire inside the chimney flue, it will cause a chimney fire. Although any amount of creosote can ignite, sweeps get concerned when enough creosote accumulates to sustain a long, hot, devastating chimney fire.

Creosote fires usually occur when there is a buildup of creosote on the walls of your chimney. When this happens, the creosote can act as a wick and draw the fire up into the chimney.

How to Prevent Creosote Buildup?

There are a few things that you can do to prevent creosote buildup in your chimney:

Have your chimney cleaned regularly

You should have your chimney cleaned at least once a year to prevent creosote buildup. The best time to have your chimney cleaned is in the springtime right after the burning season.

Cleaning your chimney is best to be done by a professional. A professional who is qualified and certified will have the proper equipment and expertise to clean your chimney safely and effectively.

Some cities and towns even have laws that require chimneys to be cleaned by a professional.

cleaning chimney professional

Because improper chimney cleaning will not help prevent creosote buildup and can actually make the problem worse. Therefore, it is best to leave this job to a professional.

Use dry, seasoned wood

When burning wood, make sure that it is dry and seasoned. Wet or green wood has higher moisture content and will produce more creosote than dry, seasoned wood.

stacked birch logs

Because driving trapped water in log cells requires so much energy, most of the heat generated by burning wet wood goes into vaporizing the water, not into heating your home.

As a result, greenwood keeps the ensuing smoke cooler as it passes through the system. And because the water vapor in unseasoned wood condenses more readily on the surfaces of your chimney, it leads to increased creosote buildup.

Burn hotter fires

Another way to prevent creosote buildup is to build hotter fires. When the fire is hot, it will produce less smoke. And when there is less smoke, there will be less creosote buildup.

burn hotter fires

You can build a hotter fire by using dry, seasoned wood and by opening up the damper. This will allow more oxygen to get to the fire, which will make it burn hotter.

You can also use a high-quality firestarter to help get the fire going and make it hot quickly. Good firestarters like Fatwood or Firestix will help you get a hot fire going quickly and efficiently.

However, I would recommend utilizing clean liquid fire starters like acetone since they will not produce any harmful chemicals. Most brand-name starters contain harmful chemicals that can be released into the air when burned.

Acetone is a great alternative since it is clean and much more effective than commercial starters. Please note that working with acetone can be dangerous, so use only small amounts and make sure to follow all safety precautions.

Don’t load the stove or fireplace too full

Combustion requires a certain amount of oxygen to work properly. If you load the stove or fireplace too full, it will starve the fire of oxygen and cause it to produce more smoke.

More smoke means more creosote buildup. So, make sure to only load the stove or fireplace with enough wood to sustain a hot fire. I know it may be tempting to load it up and let it burn all night, but this is the surest way to create a creosote problem.

Instead, it is best to build a hot fire and maintain it for a few hours. This will use less wood and actually produce less creosote than a fire that is allowed to smolder all night long.

Use a draft booster chimney fan

A draft booster chimney fan is a great way to prevent creosote buildup. It is installed on the top of the chimney and helps to create a stronger updraft.

This updraft helps to carry the smoke and combustion gases up and out of the chimney more quickly. As a result, there is less time for the creosote to condense on the surfaces of the chimney.

The draft booster chimney fan also helps to create a hotter fire. This is because the updraft created by the fan helps to bring more oxygen to the fire. More oxygen means a hotter fire, which produces less smoke and creosote.

Use certain chemical cleaners

There are chemical cleaners that can be used to help remove and control the build-up of creosote. They are typically applied either when chimneys are new or when they have been cleaned.

One of the most common chemical cleaners is muriatic acid. This is an inexpensive and effective way to clean a new chimney. It is also effective at removing light deposits of creosote.

Another chemical cleaner that can be used is trisodium phosphate. This cleaner is more expensive than muriatic acid but it is also more effective at removing heavy deposits of creosote.

Once the chimney has been cleaned with a chemical cleaner, it is important to neutralize the cleaners. This can be done by using a baking soda and water solution.

When cleaning a chimney with chemical cleaners, it is important to follow the directions on the product label. This will help to ensure that the chimney is cleaned safely and effectively.

Use a chimney balloon

A chimney balloon is an inflatable device that you can insert into the chimney. It is intended to inflate and push against all four walls of the chimney, firmly anchoring itself.

A little vent on the side of the product enables some airflow, allowing your chimney to “breathe.”

This is because the balloon forces the smoke and combustion gases to go up and around the balloon, rather than straight up the chimney. As a result, there is less opportunity for the creosote to condense on the surfaces of the chimney.

Insulate exterior facing chimneys from cold weather

Creosote buildup is less likely to occur for those who have interior-facing chimneys that are properly insulated from the cold weather.

insulation of chimney with rockwool

This is because the exteriors of the chimney will be at a higher temperature, which will prevent the formation of creosote.

However, if you have an exterior chimney, you can insulate your exterior chimneys to reduce condensation and the risk of creosote buildup.

Doing so you cannot purchase and install any type of insulation. You should use insulation with a proper fire rating and is specifically designed for chimneys.

An improper type of insulation can actually increase the chance of a chimney fire. Therefore, it is important to consult a professional before insulating your chimney.

Keep the fire going

If you let the fire die down, it will produce more smoke when you restart it. This smoke will be cooler and will have a higher chance of condensing on the walls of your chimney, which will lead to creosote buildup.

Therefore, if you plan on letting the fire continue to burn, you should keep it going by adding more wood to the fire.

Use a stovepipe thermometer

A wood-burning or multi-fuel stove, unlike many other types of heating, does not have a monitor that tells you what temperature your appliance is currently running at.

Although it may not seem to be an issue at first, not knowing how hot your stove is burning will result in either over-or under-fueling.

Over fueling a wood burner in order to maximize heat output can be a waste of time, fuel, and money. Your stove is rated for a set KW output, and attempting to increase it with more fuel would at best result in fuel being lost up the chimney, and at worst, it will over-fire, reduce the lifespan of the burner, and void the manufacturer’s guarantee.

You can avoid this costly user error by using a thermometer.

The opposite of over-fueling your stove and running it too cold is under-fueling your stove.

You’ll see blackened glass and carbon monoxide dribbling down the flue and creosote builds in the chimney, which can lead to a fire in extreme circumstances. You can avoid this possibly fatal mistake by using a thermometer.

A stove pipe thermometer is a simple and helpful instrument that magnetically connects to your flue pipe at least 300mm above your stove and allows you to easily evaluate how your stove is functioning.

Most stove pipe thermometers have a temperature gauge for precise readings as well as a visual guide to explain what these temperatures signify in terms of maximum performance and efficacy of your stove and fuel.

Use a chimney liner

A chimney liner is a long tube that is inserted into your chimney. It is typically made of stainless steel or another type of metal.

The liner helps to create a barrier between the flue gases and the chimney wall. This will help to prevent creosote buildup on the chimney walls.

A chimney liner can also help to improve the draft of your chimney. This is because the liner helps to create a smooth surface for the flue gases to travel up. A chimney liner can also help to improve the efficiency of your stove or fireplace.

This is because the liner will help to keep the heat from escaping up the chimney. A properly sized and installed chimney liner will also help to prevent chimney fires.

Use a stove with a good draft

The draft of a stove is the amount of air that is drawn into the firebox. The draft helps to keep the fire burning hot and prevents the formation of creosote.

A good draft is typically achieved by having a tall and narrow firebox. The taller the firebox, the greater the draft.

The draft can also be increased by installing a stove with a blower. A blower is a device that helps to force air into the firebox. This will help to keep the fire burning hot and will prevent the formation of creosote.

Control the path of the air supply

Restricted or blocked air vents can cause creosote to form. Make sure that your air vents are not restricted or blocked.

Creosote is more likely to form in fireplaces if the damper isn’t opened wide enough or if glass doors are closed.

The stove air supply can be restricted by closing the stove damper air inlets too early and too much, as well as by improperly using the stovepipe damper to restrict airflow.

Use a spark arrester

Spark arresters are noncombustible screens that fit over the flue of a wood-burning appliance and help to prevent sparks from exiting the chimney.

They work by cooling the sparks and stopping them from igniting any combustible materials that may be in the chimney.

Keep your chimney free of debris

Make sure that your chimney is free of any debris, such as leaves or twigs. This can help to prevent creosote buildup.

Have a rain cap

A rain cap is a metal cover that fits over the top of your chimney. It helps to keep water from entering the chimney preventing moisture build-up which can lead to creosote buildup.

Use proper tiling inside the chimney

If you have a tile-lined chimney, make sure that the tiles are in good condition and are properly sealed. This can help to prevent creosote from seeping through the cracks and forming on the inside of the chimney.

Don’t burn garbage or plastics

You should never burn garbage or plastics in your fireplace. These can produce toxic fumes and cause creosote to build up. You should also avoid burning cardboard boxes, wrapping paper, or any other type of paper in your fireplace.

Check for nests, animals, and blockages

You should also check your chimney for any blockages, such as nests or animals. These can cause problems with the draft and lead to creosote buildup if they are not removed.

Have a working smoke detector

I can’t emphasize enough the importance of having a working smoke detector. A smoke detector can save your life in the event of a fire that is about to start.

Have a working carbon monoxide detector

Carbon monoxide is a colorless and odorless gas that can be deadly. That’s why it’s important to have a working carbon monoxide detector in your home.

There are many types of carbon monoxide detectors on the market, and they aren’t expensive. I would opt for at least two detectors just to be on the safe side.

There are battery-operated or plug-in models, both are fine. However, if you have a power outage, the battery-operated models will still work. But if you have a battery-operated model, make sure to check the batteries regularly.


Creosote is a flammable substance that can build up in your chimney and cause fires.

To prevent creosote buildup, you should use a stove with a good draft, control the path of the air supply, use a spark arrester, keep your chimney free of debris, have a rain cap, use proper tiling inside the chimney, and don’t burn garbage or plastics.

You should also check for blockages, such as nests or animals. And finally, make sure to have a working smoke and carbon monoxide detector in your home. By following these tips, you can help to prevent creosote buildup and keep your family safe.

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