How to Replace a Brick Mantel

Clear anything breakable from the room. Set a drop cloth onto the floor in front of the fireplace to collect any debris loosened from the mantel. Put on a pair of heavy work gloves, safety goggles and a face mask for protection from injury.

Remove the bricks making up the mantel beginning with one of the corner bricks along the top row. Remove all mortar surrounding the brick using the tip of a cold chisel. Place the chisel onto the mortar line and then tap the chisel with the hammer to cut through the mortar in the joints surrounding the bricks. Work your way down the sides of the brick and then along the base, cutting through the mortar until you reach the layer of mortar beneath the brick.

Slip a pry bar into the cleared joints and apply upward pressure to pry the brick away from the mortar holding it in place. Pull the brick free and set it aside for disposal. Proceed along the top row, removing the side mortar and then the bottom mortar row before pulling each brick free. When you’ve cleared the top row, move down a row and repeat the process, continuing row-by-row until you’ve removed all of the mantel bricks, leaving only the thin layer of thinset against the fireplace face.

Chip away the thinset mortar with the hammer and chisel, holding the chisel at a 45-degree angle to the surface of the thinset to avoid gouging the fireplace face bricks beneath the thinset layer. You may be unable to clear all of the thinset from the fireplace using just the hammer and chisel, leaving a thin rough layer of thinset residue behind.

Remove the thin layer of thinset from the fireplace with a power sander and coarse sandpaper. Run the sander over the surface, sanding off the thinset until only the brick of the fireplace face remains. Wipe the surface clean of dust with a piece of cloth.

Measure the fireplace opening with a tape measure. Check with a local building inspector to determine the necessary clearance codes for your mantel if it’s made of a combustible material such as wood. The mantel will require a certain clearance space between the edge of the mantel material and the fireplace opening if combustible. Order a replacement mantel that fits around the opening, and with the correct clearance space for the interior of the mantel that surrounds the fireplace opening.

Assemble the mantel prior to installation using the screws that came with the mantel to connect the mantel legs to the mantel shelf.

Set the mantel against the fireplace face, centered on the opening. Place a carpenter’s level on the mantel shelf and place wood shims beneath the legs of the mantel if needed to level the mantel out. Trace the outline of the location of the mantel onto the wall with a pencil, and then remove the mantel and set it aside, laying it on the shelf end with the mantel legs pointing up.

Measure the inside width of the mantel from the rear just under the mantel shelf using the tape measure. Cut a 2-by-4-inch plank with the circular saw to match the measurement. Measure the inside height of the legs from the base of the mantel to 3 inches below the top of the shelf. Cut two 2-by-4 planks to match the leg measurements. These three boards will serve as cleats to attach the mantel in place.

Measure the thickness of the edges of the mantel and place marks inside the mantel outline with the pencil at the measured thickness along the legs and shelf of the mantel to mark the mantel’s inside edges.

Place the top cleat against the wall with the top of the cleat against the new lines that mark the inside edges of the mantel top. Drill pilot holes into the brick face of the fireplace through the cleat every six inches with a 1/2-inch masonry bit, descending about 1 inch into the bricks. Switch to a screw set and drive 2 1/2-inch concrete screws through the cleat and into the bricks through each of the drilled pilot holes. Use the same process to attach the two leg cleats to either side of the fireplace.

Set the mantel back in place. The mantel should fit snugly around the wood of the cleats. Screw 2-inch finish screws through the top of the mantel shelf into the top cleat with the drill containing the screw bit. Space the screws out every 16 inches. Screw the legs onto the leg cleats by driving the screws through the sides of the legs into the sides of the cleats.

Attach edge molding to the inside edges of the mantel surrounding the fireplace opening with 4d nails and a hammer.