DIY Mantel Shelves With Crown Molding

Measure the width of the fireplace. Cut a 2-by-4-board to match the measurement. Cut two more 2-by-4-by-6-inch boards for the side of the mantel. Cut two 3/4-by-6-inch plywood pieces measuring the width of the fireplace for the top of the mantel. Use a circular saw to cut the wood or have it cut at the hardware store.

Place the long 2-by-4-inch board on your work surface on its 2-inch side. Place the two shorter 2-by-4-inch boards on top of the larger board. Make sure the boards are flush and the edges of the smaller boards line up with the outer edges of the larger board. Hammer two nails through the larger board into each end of the smaller boards to create a rectangle with one open side.

Place a plywood piece on top of the 2-by-4-inch boards. Secure the plywood by placing one nail every 3 inches. Hammer the nails through the plywood and into the boards. Turn the structure over and secure the second plywood piece on the on the other side using more nails in the same spacing.

Cut a piece of crown molding the same width of the fireplace. Miter cut the ends at 45-degree angle using a miter saw. Cut two more pieces of crown molding measuring 6 inches long. Cut one end of each 6-inch piece flat and the other end mitered at a 45-degree angle.

Apply joint compound to the back of the width piece of crown molding. Press it to the long 2-by-4-inch board. Attach the shorter pieces of crown molding to shorter boards. Press the mitered ends against the mitered ends of the longer crown molding.

Paint or stain the wood and crown molding the desired color. Let it dry overnight.

Cut a piece of 2-by-2-inch board measuring 2 inches shorter than the width of the fireplace. Attach the board to the wall 6 inches above the top edge of the fireplace. Ensure the board is level. Use 4-inch nails spaced every 3 inches down the length of the board.

Lift the mantel to the 2-inch board. Rest the top plywood piece on the 2-inch board. Hammer nails through the plywood into the 2-inch board. Place the nails every 2-inches.