Stages of soot

Many homeowners know the build-up of creosote inside a chimney is dangerous. It can cause poor chimney performance and even lead to a chimney fire if left untreated. What many may not know are the different stages of creosote build-up and how it can impact their chimney service. If you haven’t had your chimney serviced in a while, there’s likely more going on inside your chimney than a light coating of creosote and soot. You could have a serious problem on your hands. Knowing the different stages of creosote build-up will help you further understand what a certified chimney sweep does. Here are the different stages of creosote build-up and a quick look at how we treat them. 


Creosote is a by-product of burning wood in your fireplace. There’s no way around it. The first sign that it’s building up in your chimney is a dusty soot coating the inside of your chimney. While this level of creosote inside your chimney isn’t necessarily dangerous, it’s important to act in a timely manner to have it removed. A certified chimney sweep will remove this level of creosote build-up easily. 

The Sweep Guy


The second stage of creosote build-up can look like tar flakes on the inside of your chimney. This level is where creosote starts to get concerning. If you have this level of build-up inside your chimney, it will take a little more effort to remove it. A certified chimney sweep will need to bring much stiffer brushes and possibly some special tools to scrape the build-up off the inside of the chimney. In many cases, the chimney sweep may use a special rotary chimney cleaner power tool to ensure all the stubborn build-up is removed. 

The Sweep Guy


The final stage of creosote build-up looks like a thick coating of tar in the chimney. It can even look like it’s dripping down the sides of the chimney. This is because as it heats up, the creosote can actually melt into a wax-like state. This thick coating can cause a fire to occur inside the chimney, which is extremely dangerous for your home. A certified chimney sweep will have the necessary tools to remove this level of build-up. With this level of build-up, it can make sense for the homeowner to replace their flue liner, which can add significantly to chimney maintenance costs. It’s smarter, safer, and cheaper to have your chimney swept well before creosote build-up reaches this point. 

Stage 3 soot (Creosote)