Smoke and soot are well known to stain things black. But creosote is something entirely different. Soot is formed at temperatures lower than 284 degrees Fahrenheit. It’s a dark powdery dust that stains things, but it is not sticky. Creosote is very sticky and tar-like. It’s not powdery at all. So why is creosote dangerous?

Creosote has three different stages. You need to understand these stages in order to understand how it sticks to the walls.

  • Loose flaky pieces of unburned wood get stuck to the interior of the flue due to condensation as they move up the chimney with smoke and other gases.
  • Condensation turns it into a tar-like deposit which is very difficult to remove without the use of specialized brushes or scrapers.
  • Time passes, condensation evaporates, and the creosote hardens. It’s extremely difficult to remove at this point and may drip back into your fireplace if it gets too hot.

Creosote should look smooth and slick when you look at it with a flashlight. Start by shining a very bright flashlight up or down your chimney. Make a special effort to see the interior walls of the flue. Any shiny black substance you see is creosote.

Creosote is essentially very small pieces of unburned wood. All it takes is one ember or very high temperatures to start a chimney fire. A chimney fire may not sound too frightening or serious until you realize that there are wooden beams beside your chimney between the ceiling and the roof. Those wooden beams and supports can catch fire and cause a house fire very quickly. Always do what you can to prevent creosote buildup and call on a chimney sweep to clean the chimney once a year.

Is Creosote Toxic?

Creosote does carry some health implications that you need to be aware of if you plan to clean your own chimney. Here are the most common symptoms associated with exposure to creosote:

  • Skin or Eye Irritation: Creosote is very acidic. Skin rashes and eye irritation are very common. The eye irritation symptoms may mirror chemical burns.
  • Respiratory Symptoms: Creosote particles are very small and can eventually lead to infection and other respiratory problems.

Creosote is also a carcinogenic, meaning it could eventually lead to cancer. We wanted to mention this, but not really focus on it, because even in a home with a poorly maintained chimney it’s unlikely that you would be exposed to the extent that you’ll be at risk.

Lou Curley’s Chimney Services in Drexel Hill

Soot and creosote will build up in your chimney if you use your fireplace or another wood-burning appliance at all. The only way to avoid it entirely is to never use the chimney, but where’s the fun in that? We have two CSIA Certified chimney sweeps standing by to assist you with your chimney needs. Give us a call at 610-626-2439 to schedule an appointment for a chimney inspection or cleaning. We provide chimney services throughout the Main Line region.