Creosote is the enemy of a well functioning chimney and can cause catastrophic fires. What is it? Where does it come from? How can it be prevented? And how is it removed? We’ll cover those first questions in this post and follow up with more answers next week.
Creosote is a chemical byproduct of the distillation of tar. Burning wood (which contains tar) effectively distills the tar releasing it in the smoke. There are different types of creosote-burning coal creates a specific type of creosote, as do oil and peat. It has a number of commercial uses in medicine as an ingredient in expectorants, antiseptics, anaesthetics, and laxatives, and is used in the preservation of meat. The word creosote comes from the greek words “kreas” (meat) and “soter” (preserver).
Burning wood in a stove or fireplace will create creosote, but there are ways to minimize the amount of creosote your fire produces. One of the most common causes of excess creosote is burning green or unseasoned wood. Unseasoned wood contains more moisture which results in the fire burning at a lower temperature, and cooler fires produce more creosote which dries more slowly in your chimney. Anything that allows a fire to smolder (such as a damper that is not completely open) can also contribute to increased creosote production. Another cause is improper installation of a fireplace or stove. If a flue is too large the draft may be insufficient to keep the fire burning at a high enough temperature. If you’ve had problems with creosote build-up despite burning well seasoned wood, you may need to have us come and check the installation of your stove or fireplace.
Check back next week and we’ll talk about levels of build-up and how it’s removed.