How to Rebuild or Cover Up Old Brick Around a Fireplace Mantle

Remove any screws or nails from the mantel around the fireplace. Slide a small prybar between the wall and the mantel and pry it away from the wall. Move this piece a good distance from the fireplace to a safe area.

Start with clean brick. Remove as much dirt and as many stains as possibly with a simple soap and water solution. Be sure that the brick has been completely rinsed and dried.

Transfer liquid masonry bond to a plastic paint pan. Dip a paint roller into the masonry bond and roll it all over the bricks of the fireplace surround. Cover all of the bricked surface evenly.

Wait for the masonry bond to prep while you mix the concrete. Combine the dry concrete and the directed amount of water (this will be different based on your brand and amount) in a plastic bucket. Mix the concrete with a shovel so that the consistency is uniform throughout.

Trowel concrete onto the surface of the bricks with a straight metal trowel. Build up the concrete so that it is approximately 3/8-inch thick and even all over. Rub the trowel back and forth over the surface of the concrete to smooth it.

Wait 20 to 30 minutes. Hold a notched metal trowel lengthwise at a 45-degree angle and drag it horizontally across the concrete in straight lines from top to bottom. Create small trenches this way so that the final application of concrete adheres well.

Apply more concrete on top of the ridges' surface, using the straight trowel. Make this layer of concrete ½-inch thick, again keeping it even over all of the formerly bricked area. Smooth this top layer in the same way that you did the first layer of concrete in Step 5.

Allow the concrete to cure (this is the name for the drying process) undisturbed for approximately 5 days. Reinstall the fireplace mantel. Double-check the concrete for any signs of moisture or improper application before using the fireplace again.