Creosote is the natural by-product of burning wood, it includes tar droplets and other organic compounds. Tar droplets make up a major component of the smoke from burning wood this is why leaving a fire to slumber overnight is inadvisable. Heavy tar and creosote build up inside a chimney is putting you more at risk of a chimney fire. Tar and other vapours can condense within the interior of the appliance and it’s flue system, these deposits are usually brown/black and are called creosote.
Contributing Factors of Creosote
- Slumbering a fire; turning all the air vents down so your fire builds up more smoke is inadvisable. In general the smokiest fires contribute to the most creosote.
- Moisture content of fuel; not too dry or too wet, in the region of 14-20% moisture content.
- Flue gas temperature can be affected by many factors including chimney type, size, location and construction.
- The amount of time that smoke lingers in the chimney; the longer the time, the greater chance of creosote and tar build up.
- To minimise the build up of creosote use dry, well seasoned wood with a suitable chimney in a suitably sized appliance for the room making sure the fuel load is correct, the air supply is met and the temperature balance does not exceed 350°C as it a my cause a chimney fire.
Reasons to remove creosote
- Increased risk of chimney fire.
- Creosote is acidic and corrosive and can eat into brick work and mortar lines giving you staining on the chimney breast and deterioration of the chimney itself.
- Easier for chimney to be swept, making it less time consuming and keeps costs down.