How to Build a Wood Mantel

A simple mantel shelf can be completed and installed in a weekend, with startling aesthetic results. Choose wood that compliments the existing wood and stone work then find moldings with similar details to blend the new mantle into your space. The following example is suitable for fireplaces up to 30 inches wide. For a different-size space, just widen or narrow the front and top pieces.

Things You'll Need

• Plywood or hardwood for the mantel shelf
• Table saw or circular saw
• Miter saw
• Tape measure
• Pencil
• Wood glue
• Hammer and finish nails
• Wood molding
• Primer
• Paint
• Stain
• Finish
• Sandpaper
• Random orbit sander

Instructions

Building the Mantel Shelf

1. Cut your pieces from ¾-inch hard wood or cabinet plywood. For our example we will use a shelf that's 40 inches wide and 10 inches deep. Start by using a table saw or circular saw to cut a piece 38 ½-by-9 ¼ inches. This will be your mantle shelf top.

2. Cut one piece 40-by-6 inches, mitering both 6-inch edges at 45 degrees. Cut two pieces 9 1/4-by-6 inches, mitered at one 6-inch edge at 45 degrees. Angle miters to the center of the piece. Set and lock the saw at 45 degrees. Hold material firmly down to the table and against the fence. Start the saw and make your cuts with steady motions. Keep fingers clear of the blade.

3. Use wood glue and finish nails to attach the three mitered pieces into an open rectangle 40-by-10 inches. Use the round side of a piece of pipe or a large wooden dowel to press the mitered edges into each other to make tight joints. This is the mantel shelf skirt.

4. Set the skirt on a firm level surface. Place the shelf on top with all three edges flush. Glue and nail the shelf into the top of the skirt. You will now have a four-sided box that's 40-by-10-by-6 ¾ inches. This is your mantel shelf.

Adding The Molding

1. Add a flat-back, ¾-inch-thick molding, such as bullnose, baseboard or casing to the top edge of the shelf. Your local home center sells a variety of moldings by the foot. Cut one piece mitered at both ends the length of the shelf (40 inches inside to inside of the miters).

2. Mark for miters by holding your molding flush against the top edge of the shelf face. Position it with at least 1 inch on either side and mark the edges of the mantel shelf on the back of the molding. Cut the inside (short side) of your miters on these lines.

3. Cut two pieces for the short ends, mitered at the front end. Mark similarly to the long piece. Cut the short side of the miter on the line.

4. Glue and nail the molding to the shelf. Attach the short pieces first, flush with the top of the shelf. Add the front (long) piece flush with the top of the shelf. Press the mitered edges together.

Finishing the Mantel

1. Fill nail holes with wood filler. Sand the whole mantel. Use a fine grit paper on a random orbit sander for best results.

2. Apply primer before painting. Use semigloss latex in your choice of colors for a nice finish. Follow the manufacturer's instructions for application and drying time.

3. Apply stain to the shelf with a quality bristle brush. Wipe excess stain from the surface of the shelf. When stain is thoroughly dried, add at least two coats of semigloss poly or varnish.

References

• Floating Shelf Construction
• Building a Wood Mantel