How to Drill a Mantel Bracket

Lay the mantel face down on the floor. Measure the length of the mantel's hollow backside. Transfer this measurement to a 2-by-4-inch board. Cut the board to length with a saw. Test fit the board against the mantel. Repeat this step for each of the mantel's legs. You now have three cleats.

Set the mantel into position around the fireplace. Trace around the mantel with a pencil and move the mantel aside. Measure the width of the mantel from the top edge to the hollow portion. Mark this thickness on the wall inside the tracing you just made. Repeat with the mantel's two legs.

Aim a laser level horizontally at the wall. Line up the laser with the mark near the tracing's top edge. Set the cleat you cut to fit behind the mantel against the wall. Line up the cleat's top edge with the laser. Drill two 2 1/2-inch deep 1/2-inch pilot holes through the cleat and into the wall about 2 inches in from each end, using a hammer drill and masonry bit. Drill two more 1/2-inch pilot holes evenly spaced between the first two holes. Drive a 2 1/2-inch masonry screw through each pilot hole.

Adjust the laser level so it hits the wall vertically. Aim the laser at the mark you made inside one of the mantel's legs. Secure the leg cleat to the wall the same way you secured the mantel cleat to the wall. Repeat with the mantel's second leg cleat.

Position the mantel over the cleats. Drive 2-inch finishing screws through the top of the mantel and into the mantel cleat. Place the screws approximately 16 inches apart. Drive finishing nails through the legs' sides and into the cleats, spacing them about 16 inches apart.