Creosote is an oily liquid, which is emitted as volatiles; when wood or fossil fuels like coal, is burnt at low temperatures. In case of chimneys, these are released with the smoke. The smoke rises through the chimney, and gets cool, causing condensation of the volatiles on its inner walls. This black and oily residue on the chimney walls is termed creosote.
In the long run, the creosote buildup on the inner walls of the chimney thickens, affecting the airflow that is necessary for burning wood at high temperatures. Such accumulation can also cause chimney fires. So creosote should be removed at regular intervals, for the proper functioning of the chimneys and to avoid chimney fires.
How to Remove Creosote
Wood creosote is a yellowish greasy liquid with a smoky odor and burned taste. It is used to protect wood from mold during the rains; and from shrinkage and losing sheen, when exposed to sun.
Another type of creosote is distilled from crude coke oven tar. This thick, black, oily liquid is commercially used as a wood preservative, as animal and bird repellents, and as insecticides.
However, the carcinogenic nature of this substance has led to discontinuation of its use, in some countries. Creosote in the chimneys has to be removed at regular intervals for fireplace safety. Even though there are professionals, who can be hired for the task; you can do it for yourself.
As creosote exposure can cause skin rash and burning sensation in the eyes, you have to take sufficient precautionary measures, before venturing on this task. Wear some old clothes, and use safety glasses, a respirator, and gloves.
Get a chimney sweeping brush of the right size, and cover the face of the fireplace, to avoid any dirt from entering the house. Start cleaning from the lower part of the chimney, by rotating the brush. Once the lower part is done, go to the top, and start cleaning from the top to the bottom. You can use a flashlight to check whether any residue is left.
Once the cleaning is done and the dust has settled, remove the covering of the fireplace. Use a wet/dry vacuum (not the household one) for removing the debris and dust. If the buildup is stubborn and cannot be removed by the brush, you may hire professionals.
Another method for creosote removal is to use chemical products, that are added to the wood, before burning. The ingredients in the chemical products attach to the creosote, and transforms it to burnt ash, which is harmless. However, you have to follow the instructions of the manufacturers, while using such products.
From Glass and Clothing
Creosote buildup can be found on fireplace doors made of glass. In such cases, it can be removed with a razor blade. After that, spray some window cleaner on the glass surfaces, and dry them with a towel or a clean rag. If your cloth is stained with creosote, never wash it in a washing machine.
Apply some oil or butter over the stained area, and wipe the stain with lifting motions. After that, use some warm water and detergent to wash the spot. The next step is to launder the cloth in a small load, before drying. However, make sure that almost 90% of the stain is removed before drying.