Directions to Build a Fireplace Mantel

Measure the area around the fireplace. Determine the mantel dimensions. Decide on the thickness of the mantel shelf and subtract the shelf's thickness from the height. This will give you the mantel leg length.

Cut out two pieces of medium-density fiberboard (MDF) for the top and bottom of the shelf. Cut another piece of MDF for the front of the shelf. Cut two pieces for the sides of the shelf; cut these two pieces again to match the width of the shelf top and bottom pieces.

Construct the pieces into a long, backless rectangular box using small nails.

Place decorative moldings on top of the mantel shelf to determine the most pleasing arrangement. Mark the moldings. Miter-cut them to specifications. Glue the moldings to the mantel, fitting mitered edges together.

Cut six pieces of MDF according to the desired height and width of the mantel legs. Construct three of the pieces into tall, thin, backless, topless and bottomless boxes for each leg.

Cut the staircase posts to match the leg length. If they are too short, construct small boxes to boost their height. Glue the posts to the face of the mantel legs.

Sand and paint or stain the kit pieces. Assemble for installation.