Our Company Blog

The Dangers of Chimney Creosote

Has your chimney been inspected this fall? If you have a wood-burning appliance, you likely know the importance of having your chimney swept and inspected every fall before you light a fire, to ward off a potential chimney fire. You also might have heard the term “creosote” bandied about by your sweep or in reference to chimney fires. But what exactly is creosote? How does it form? And why is it so dangerous?

What is creosote?

Creosote is a natural byproduct of burning wood. It’s a tar-like substance that sticks to the walls of your chimney and builds up over time. Creosote can be sticky and brown or smooth and black.

How does creosote form?

Every time you burn a wood fire in your fireplace, creosote builds up on the walls of your chimney. As smoke travels up your chimney, it cools, and condensation forms on the walls of your chimney. That condensation contains all of the chemical elements put off by your wood fire. As your chimney continues to cool, the condensation hardens into creosote.

Why is creosote so dangerous?

The No. 1 danger associated with creosote is chimney fire. Creosote is highly combustible, and when it builds up to a measurable degree within your chimney, it poses a major fire risk. Creosote caked on the walls of your chimney can ignite either when the temperature within your chimney spikes to high enough temperature, or when a stray ember from the fireplace makes its way into the chimney. Ultimately, creosote is considered the primary risk factor for a chimney fire.

Creosote does come with some health risk factors, as well, but because the average homeowner using a wood-burning fireplace doesn’t come into contact with creosote, the health dangers of creosote are generally negligible for those who aren’t handling it. Creosote can irritate eyes and skin upon contact, or it can aggravate the lungs if inhaled. Ingesting creosote can cause stomach pain or even liver or kidney damage.

How can you reduce the dangers of creosote?

You probably know that the best way to reduce the dangers of creosote, namely the dangers of a chimney fire, is to have your chimney swept and inspected regularly. As those in the chimney industry are fond of saying, “Clean chimneys don’t catch fire!” In between sweepings, you can reduce creosote buildup in your chimney by burning dry, seasoned firewood. Seasoned firewood burns hotter and more cleanly, while wet firewood lets of more smoke and steam, leading to a more rapid buildup of creosote in the chimney.

Keep your home safe from the dangers of creosote by having your chimney swept and inspect before you burn a fire this fall! If you’re due for a chimney sweeping, call Your Chimney Sweep to schedule an appointment today!

Tips for Properly Storing Firewood

While the first fire of the fall is months away, if you cut and prepare your own firewood, you are likely hard at work readying fuel for next winter’s fires. You also likely know that there’s a lot more to preparing firewood than cutting down trees. There are several steps you should take to properly season and store your firewood to create the best firewood for your fireplace or woodstove.

Cut and split your firewood to the right size.

One advantage to cutting your own firewood is that you can cut it to the proper length for your fireplace or woodstove. Ideally, firewood should be three inches shorter than the width of your firebox. Once it is cut to length, logs should be split to a width of 6 inches or less.

Stack wood in a single layer, where it is exposed to light and wind.

Wood needs to be properly seasoned before it is fit for a fireplace. That means the moisture content of the wood should be less than 20 percent. To achieve that, wood needs to be exposed to wind and sun to evaporate the moisture out. Stack the wood loosely in a single layer. Wood should be left uncovered while it is seasoning.

Season firewood for at least one season.

It takes at least one season of drying for wood to be seasoned and ready for the fireplace. You will be able to tell if wood is seasoned if it is lighter, dull gray in color, slightly cracked and if it makes a hollow thumping noise when struck together.

Save enough space.

While seasoning firewood can be stacked nearly anywhere in the yard or field, you will need to have space to store your properly seasoned firewood for the winter. A wood-burning home uses three cords of wood or more each winter, which takes up a lot of space.

Store seasoned firewood off the ground and covered.

Seasoned firewood should be stacked off the ground, and it should be covered to prevent it from absorbing additional moisture. A covered woodshed or porch is ideal, but wood can be stacked outside on a wood stacker or atop a base of pallets and then covered securely with tarps. Never store firewood against your house or in your house, as that can introduce bugs and other pests to your home. Make sure wood stays dry to prevent the growth of mold, which can go airborne when burned, posing a health hazard.

Properly seasoned and stored firewood is crucial for keeping your fireplace or woodstove burning efficiently and cleanly. Without it, you won’t realize the maximum heat output from your fireplace, and you will cause flammable creosote to build up quickly in your fireplace. You will be able to tell if your firewood has been properly seasoned and stored when you burn it — Dry wood will let off the pleasant crackling sound associated with a traditional fireplace fire, while wet firewood will hiss and steam.