How to Build an Oak Mantel With Legs

Measure the length and width of the firebox, where the fire burns. You will position the mantle above the firebox. Assume the firebox is 50 inches wide and 47 inches tall.

Design the mantel and leg ensemble. Assume you want the mantel to be 70 inches wide with legs supporting each end going down to the base of the fireplace. Assume each leg is 5 inches wide, giving 60 inches of space between each leg across the firebox.

Assemble the components of the frame to which you will attach the oak pieces. Use three-quarter-inch board for the frame. Cut two planks 5 inches wide and 50 inches long as the side frame for the legs and top part of the shelf. Cut one plank 3 inches wide and 60 inches long for the top frame that will go between the two side-frame planks. The mantel will secure to three parts of the frame, giving it stability: the top center plank and each end.

Mount the frame planks. Measure and mark six holes in each plank: two in the middle of the plank 3 inches apart and two 1 inch from each end 3 inches apart. Drill these holes, and then hold the boards up to the fireplace surround, and mark the holes on the wall. Drill the holes marked on the wall, starting with the top-center plank. Screw the frame top and legs to the wall. The frame is ready for the oak mantel.

Build the legs. Cut two 5-by-5 posts 47 inches long. Place two flush mounts on one side of each leg that will attach to the frame. Hold the leg up to the frame, and mark holes matching the mounts. Drill the required holes, and secure the mounts with two to four screws – mounts vary.

Drill a hole in the center top of each leg where the mantel secures to the each leg. Position each leg on the frame, sliding the leg from above into each mount.

Build the mantel shelf. Cut the top shelf 70 inches long, using a 1-inch-thick oak plank.

Measure and mark the top of the mantel every 6 inches a half inch from the edge. Drill screw holes at these marked spots. These holes are where the mantel sits and attaches to the top edge of the frame built around the firebox and surround.

Match and mark the drill holes of the mantle on the top edge of the frame. You also need two drill holes for each leg to secure to the mantel. Secure the top shelf in place by screwing in trim-head screws that sit flush to the shelf.