Clean a limestone fireplace by emptying the ashes, vacuuming the stone, protecting the surrounding area and scrubbing with trisodium phosphate. Since limestone is porous, it allows stains to soak into the stone.Continue Reading
Wait until the fire has died and the ashes are cool before beginning the process. Remove any unburned firewood and ashes from the fire pit before proceeding.
Attach a soft brush to the vacuum cleaner, and vacuum the stone to remove as much dust as possible before wetting the stone.
Place towels around the fireplace on the floor to catch any splatter or drips that form as you work. Wear eye protection, rubber gloves and clothing that prevents the cleaning solution from touching your skin.
Follow the package directions for mixing the trisodium phosphate in water. For light-colored limestone, add a small amount of bleach to the solution. If the fireplace is dark, do not add the bleach, as it may lighten the color of the stone.
Apply the solution to the stone using a sponge and allow it to soak a few minutes. Use a scrub brush dipped in more of the cleaning solution to scrub each stone and the mortar between stones.