DIY Concrete Fireplaces

Mix together one part of mild dish detergent and two parts water in a bowl. Dip a nylon-bristled scrub brush into the mixture. Scrub the whole existing surround until it is perfectly clean and wipe it thoroughly with a damp cloth to remove the soap.

Let the surround dry 24 hours. Pour liquid concrete bonding agent into a paint pan. Use a large paintbrush to apply a thin, even coat of the bond to the fireplace surround in straight lines.

Allow the concrete bonding agent to activate; this will take approximately 15 minutes. Use a straight metal trowel to scoop up about 2 cups of prepared concrete. Apply the concrete to the entire fireplace surround, making the layer about 3/8-inch thick.

Smooth the surface of the concrete with the trowel and let it cure for 30 minutes. Drag the edge of a clean, notched trowel horizontally across the face of the fireplace surround from top to bottom, creating textured lines. Switch to the straight trowel and apply a second layer of concrete, ½-inch thick, to the fireplace surround.

Use the flat side of the trowel to smooth the final surface of the concrete. Wait three to five days to let the concrete dry completely. Check that the concrete has cured completely before using the fireplace.