Stains on fireplace stones are generally caused by the build-up of a substance called creosote, which is a thick, sticky residue. Creosote can stain your fireplace and cause numerous other problems, including chimney and house fires. Cleaning your fireplace thoroughly two or more times each year can help reduce or prevent a creosote build-up, and it helps remove the stains it creates. To remove stains from fireplace stones, there are several simple steps to take.
Fill an empty spray bottle with hot water and thoroughly wet the stone you are cleaning.
Use a wire or stiff-bristle scrub brush to clean the stone and dislodge any built-up creosote, ash or other debris.
Spread eucalyptus oil on the stone. Eucalyptus oil breaks down creosote and makes it easier to remove.
Allow the eucalyptus oil to sit on the stain for 30 minutes to an hour.
Spray the stone with hot water a second time and use the scrub brush to rub away the oil and the stain.
Wipe the fireplace stone dry with a clean cloth or towel.
Repeat these steps if stains remain on the stone.