creosote build up inside a chimney flue


Originally contributed by Jeff Butler • last updated 12/17/2020

If you’ve ever owned or operated a wood burning fireplace, you may also be familiar with terms such as creosote or creosote log. That’s because creosote build-up in a chimney flue can not only be problematic, it can be potentially hazardous, as well.


When it comes to wood burning fireplaces, the term creosote refers to the tarry residue that forms on the interior walls of a chimney (or chimney lining) from the smoke and gases cooling and settling. Creosote build-up is problematic because it reduces the airflow through the flue, creating conditions that lead to further creosote build-up, and causing fireplace inefficiencies. Creosote is also highly flammable and is known to cause chimney fires, leading to structural damage or worse. Additionally, there are also concerns that exposure to creosote can cause health related issues, such as skin and eye irritations.

How To Reduce Creosote Build Up and Keep Your Fireplace Clean

Having a wood burning fireplace inside your home might seem like a good idea but they can quickly become inefficient and dangerous if not properly maintained. Here’s how you can reduce creosote build up and other potential problems:

  • Burn only dry, well-seasoned wood as it produces less smoke, burns more efficiently, and helps prevent creosote build-up in your chimney flue. You can also burn creosote logs (creosote sweeping logs), which help prevent creosote deposits and improve your chimney’s performance.
  • Inspect your chimney annually and hire a professional chimney sweep to clean out your chimney flue. Although there are DIY kits available, a professional chimney cleaning service will be able to identify potential problems.