How to Remove Cement Off of a Stone Fireplace

Cover all surfaces around the fireplace with a drop cloth to protect from dust created during removal. Tape drop cloths over the doorways to keep the dust from moving into an adjacent room.

Pry up as much cement as possible with a putty knife. Place the edge of the knife beneath the edge of the cement and use the knife as a wedge to force the cement upward. If the putty knife isn't strong enough to work as a wedge, then use a small prybar instead.

Break up the cement for easier removal, using a cold chisel and hammer. Place the point of the chisel on the top of the cement at a low angle of about 20 degrees. Strike the head of the chisel with the hammer to create a crack in the cement. Work the chisel along the crack, extending it through the cement to create smaller pieces. Pry up the individual pieces using the putty knife or prybar.

Place a coarse sanding pad onto an orbital buffer. Place the buffer onto any cement remaining on the stone and start the pad rotating. Move the buffer over the cement while applying light pressure to grind down the cement until left with a layer on the stone as thin as possible, only a few millimeters thick. Move the buffer in small circles to remove the cement.

Remove the cement dust and particles with a whisk broom.

Open all windows and doors to the room and add extra ventilation fans if possible. Put on protective clothing, covering your skin completely, and put on rubber gloves, safety goggles and a respiration mask.

Mix 1 part muriatic acid with 10 parts water. Saturate the remaining cement with the diluted acid using a brush. Allow the acid to sit in place, dissolving the cement, for about 10 minutes.

Scrub the cement with a scrub brush to break it up. Rinse the acid and dissolved cement from the brick using water. The water will neutralize remaining acid as well. Continue rinsing the stone until the acid no longer bubbles.