Chimney Creosote Removal – Buildup & Cleaning Process

Creosote deposits are common with chimneys of all kinds and may negatively impact smooth functioning when it gets severe. One of the key maintenance actions performed by chimney sweeps involves creosote removal.

This is important as it frees up these flammable chimney tar deposits, thus limiting fire outbreaks.

The state of your chimney is very important as it could have a real impact on cost, health, and safety among other things. So, a basic maintenance action such as creosote removal is key to keeping it functional.

This article will be discussing glazed creosote removal and more.

What Is Creosote In Chimney?

To have a meaningful understanding of the creosote removal process, it’s necessary to beam our searchlight on the subject matter; creosotes. This tar-like substance is a by-product of wood combustion.

Wood combustion produces various by-products.

What Does Creosote Look Like?

These by-products range from wood particles, water vapor, tar fog, minerals, and gases apart from the smoke. As they rise from a fireplace and travel up the chimney, these by-products of combustion find cooler chimney liner surfaces.

Upon reaching or finding colder surfaces, creosote condenses and solidifies.

At its initial stage or after condensing, creosote takes the form of a sticky substance. However, its form changes with time as it gets baked into a flaky form before eventually transitioning to a hard state.

Whatever stage such deposits are, they pose a significant danger with steady accumulation.

Chimney fires and by extension house fires are ignited by these. The main reason why creosote accumulation is dangerous is because of its flammable nature.

Creosotes are extremely flammable and will readily fuel chimney fires once it starts. It’s important to have these removed by a professional chimney sweep as often as necessary.

3 Stages Of Creosote Deposition

When creosote accumulates, it does so in three key stages; the flaky and dusty stage, hardened and crunchy, as well as the tar-like stage.

At whatever stage you find creosote deposits, cleaning will need to be carried out to limit risks.

Let’s take a look at each of these.

  • The Flaky and Dusty Stage

This is the first stage of creosote deposit in chimneys. As the name implies, this is the stage where the deposits arising from combustion take the form of a flaky and dusty substance on the flue lining.

At this stage, it’s easiest to clean or clear up.

Using a tool such as a chimney sweep brush, you’re able to get rid of these without much difficulty.

  • Hardened and Crunchy Stage

This is a more advanced form of creosote accumulation than the flaky & dusty stage.

Here, the deposits look similar or resemble tar. It’s a bit harder and becomes crunchy. There’s a firmer grip on chimney walls compared to the previous stage.

Having it removed will require an appropriate tool. One of such is a rotary loop joined to a drill.

  • Tar-Like Stage

Do you have black tar coming down the chimney?

This is the end stage of creosote accumulation on chimney liners.

Due to combustion heat, creosote gets baked into a hard tar-like substance. It’s more refined. You mustn’t allow creosote deposits to reach this stage.

When it does, it becomes problematic to remove. Plus, it fuels any chimney fires at the slightest ignition. It’s important to have a licensed and professional chimney sweep to get the job done.

Because of the damage that may result from getting these off, relining may be necessary.

How much creosote is dangerous? Well, this third stage is the most harmful.

Who Performs Creosote Removal From Chimney?

As always, any chimney-related maintenance including creosote removal must be handled by a professional. A CSIA (Chimney Safety Institute of America) certified chimney sweep should be called upon for this task.

Creosote removal is part of the chimney cleaning process that must be handled by trained experts.

Therefore, homeowners shouldn’t consider DIY strategies at all. There are risks attached to the job. Plus, it’s a messy and stressful process that could overwhelm you.

So how do you get rid of creosote buildup?

Cleaning Creosote From Chimneys

Based on the stages of creosote formation mentioned earlier, removal will need to be done systematically. The best stage to clear up or remove creosote is when it’s at the first stage.

Here, it’s flaky and dusty and won’t firmly adhere to chimney walls.

At this stage, a specialized brush used by chimney sweeps should easily get rid of creosotes. However, things begin to get a little more challenging at the second stage where creosotes are crusted to chimney walls. These are firmly attached, though not as much as the last stage.

Removal of such creosote will require a different approach than the first.

Because you’re dealing with more tar than soot, special solvents may be applied to help loosen up gunk layers. Professional chimney sweeps know what solvents need to be applied and at what stage to do this.

When creosote becomes so baked that it turns glossy or glazed, it has been highly refined.

Getting rid of glazed creosote is very challenging for chimney sweeps. This is why it’s recommended that you don’t allow your chimney to deteriorate to this point.

If such creosote must be removed, some damage will be caused to the chimney liner. This is likely to alter the structure too. So, creosote removal at this stage will include repairs. This will incur added costs.

Nevertheless, it’s worth the stress.

Can Creosote Buildup Be Prevented?

It’s natural to consider the possibility of creosote prevention.

However, is this even possible? Not at all! As long as fuels such as firewood, coal, gas, etc are used, creosotes will always form. The only thing that can be done to stop it is to cease completely from using your fireplace.

This isn’t even likely as you need to keep your home heated during the winter months.

However, the level or amount of creosote accumulation can be reduced by burning dry or seasoned wood. This produces less creosote than damp wood.


Maintenance is basic to enhancing chimney efficiency.

A key maintenance practice involves making sure that yearly inspections and cleaning are observed. This must be done by a professional chimney sweep.

There you go! Creosote removal in chimneys is a basic maintenance practice that has been focused on.

We’ve discussed the various stages of formation and when to have such removed. You’ll need to seek expert help in setting the cleaning times for your chimney.

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