Text Resize

  • -A
  • +A
  • No votes yet

    How to Create a Mantelpiece

    more on woodworking safety

    Tools and Materials


    Admit it: you've been admiring these ornate display shelves in your favorite home-furnishing catalogs. But in the time it takes to order a factory-made shelf and get it shipped to your home, you could build and finish several of these shelves yourself. The materials for the shelf shown here will cost you less than $15, so you’ll save loads of money. And since you’re in charge, you can design mantelpiece shelves in any size and style you like by combining different moldings with the square-edged boards used to make top and bottom pieces. Finish up with your choice of paint, stain, or varnish, and you’ll give this project a unique style that can’t be found in any catalog.

    Photos by Stephen Carver; Illustrations by The Taunton Press, Inc.

    This article originally appeared in Taunton's Trim Transformations (2004).

    How to Make

    Tools & gear

    Miter boxclick to enlargePrep the miter box

    Miter box: To miter the molding you’ll need a miter box. A good miter box like the one used in this project comes with its own fine-tooth saw and costs about $40. Avoid cheaper wooden or plastic boxes that have slotted sides. If you want pro-level speed and precision, get a chopsaw. To prep your miter box for the cutting work in this project, anchor the box to a workbench or to sawhorses with some screws.Most miter boxes have holes in the feet or base for screwdown attachment.The other prep step involves attaching a plywood auxiliary fence to your saw’s standard fence. A higher fence that you can cut into will help you get more exact cuts in your molding

    What to buy

    Miter boxclick to enlargeMantelpiece illustration

    Combination square: This adjustable square is a versatile layout tool. For this project, you’ll use a combination square to mark where the top of the molding meets the bottom of the shelf board.

    Attach the front crown

    Miter boxclick to enlarge

    Drill : You'll need one to predrill holes for the hanger screws.

    Finish it up

    Miter boxclick to enlargeCut the stock

    Circular saw: You’ll need this power saw to cut the shelf board to size.To ensure smooth cuts,make sure you’ve got a finish-cutting blade in your saw.

    Miter boxclick to enlargeFront molding piece

    Paintbrush & rags: Your display shelf deserves a fine finish. A good-quality 3-in. paintbrush is what you need to apply primer and paint or stain and varnish. If you’re using oil-base paint or varnish, make sure to use a natural-bristle brush or a synthetic brush recommended for use with oil or alkyd finishes. If your finishing plans involve applying stain or varnish, also get a few clean, soft rags.

    Miter boxclick to enlargeAdd brads to the molding

    Crown molding: The molding used for this project is 9⁄16 in. thick and 45⁄8 in.wide.You’ll find crown molding in different sizes and shapes at your home center or lumberyard. Choose any profile you like as long as the overall width of the molding is at least 3-1⁄2 in.Molding is usually sold by the foot.Get a piece that’s straight and at least 1 ft. longer than the planned length of your finished shelf. You can design a mantelpiece shelf with a single molding or combine different moldings to build up a larger and more elaborate architectural detail.Here’s a design strategy that’s easy and fun: Using your miter box, slice off an inch or so of the molding or moldings you plan to use. Place these molding cross sections on a piece of graph paper, combining them with the full-scale section drawings of the other parts of your mantelpiece—the shelf, bottom, and backer blocks.This exercise will show you what the completed mantelpiece profile will look like and what the dimensions of the parts need to be.

    Miter boxclick to enlargeCut outside miters

    5/4 x 6 Pine: A 5/4 x 6 pine board is really about 1 in. thick and 51⁄2 in.wide. Look for a straight, flat, knot-free piece that’s as long as you want your shelf to be.

    Miter boxclick to enlargeInstall the bottom piece

    Brads: These tiny nails are for fastening the molding to the underside of the shelf. Buy a small box of 1-in. brads.

    Miter boxclick to enlargeAttach the side moldings

    Yellow glue: This woodworking glue will bond the molding pieces to each other and to the shelf.The brads just hold things together until the glue sets.

    Miter boxclick to enlargeFinishing touches

    Sandpaper: Buy a couple of sheets of 120 grit for rounding the shelf edges and sanding putty patches smooth.

    Miter boxclick to enlargeInstall the finished product

    Wood putty: Make sure you have some putty on hand for filling brad holes and small gaps in joints.

    Finish: For a painted finish, get interior primer and semi-gloss trim paint. Use polyurethane varnish for a clear finish. Stain or tinted varnish are other finishing options.

    Flush-mount Hardware: One piece of each interlocking pair mounts on the wall; the other is fastened to the back of the finished shelf.You’ll need two sets of flush-mount hardware for this project.

    Cut & mark the shelf board: Using a circular saw, cut the 5/4 x 6 stock to the length you choose—36 in. is shown here. Then decide how far over the crown molding you want the shelf board to extend—3⁄4 in. in this case. Use your combination square to mark the underside of the shelf board, showing where the top edge of each molding piece will fit. The proportions of your display shelf will depend on the size of the crown molding you plan to use.To get an exact idea of how high and deep the molding is when it’s installed, cut off a small section and place it against a framing square, as shown in the drawing. Now you’ll have an easy time determining what the width of the shelf should be.

    Cut the front molding piece: Make the miter cut for the left side of the front molding piece. To do this, put the molding upside down on the left side of the saw, and swing the blade 45 degrees to your right. Align the blade with your cut line, and make the cut. Holding the front molding piece in its installed position on the shelf board, mark where the opposite miter needs to be cut. Reverse the setup of your first miter to cut this opposite one.

    Attach the front crown: Start 1-in. brads into the molding, orienting them so they will go straight into the bottom of the shelf board. Put yellow glue on the narrow top edge of the molding. Holding the molding in place along your layout line, drive and set the nails.

    Cut the side molding pieces: Cut outside miters on the two pieces of molding that join the front piece. Put each piece in place, and mark where they cross the back of the shelf. Square-cut both side pieces to length.

    Cut & install the bottom piece: Using a circular saw, cut your bottom board to its finished width. Square-cut one end of the board, and hold it in place along the bottom edge of the front molding. Mark it so you can cut it to final length, then make the cut using your miter box. Attach the bottom to the front molding piece with glue and 1-in. brads.

    Install side moldings & blocks: Attach the side molding pieces with glue and brads. Make sure to spread glue generously on miter joints, then fasten the side pieces to the shelf board and the bottom. To bridge the gap between the shelf board and the bottom, cut three blocks. Space them evenly apart, and install them with glue and 6d finish nails.

    Fill, sand & finish: Fill all nail holes with wood putty; also putty up any gaps between joints. When the filler has hardened, give your shelf a thorough sanding. The shelf edges will look great if you just cup a folded piece of sandpaper in your hands and run it along the top and bottom edges. Apply primer and two coats of trim paint. Want to give the edges of your shelf a gentle curve? You can do this by using a block plane. Adjust the blade to take a light cut (you can test this on scrap stock), then plane the ends of the shelf first, followed by the shelf’s front edges.You’ll still need to complete the smoothing at the shelf edges with sandpaper, but the block plane treatment adds a nice handcrafted touch.

    Hang it up: Lightly pencil a level line on the wall where you want the top of the shelf to be. Screw your hanger hardware to the back edge of the shelf board and to the wall. Fasten into studs if possible; otherwise, attach hanger brackets to the wall with screws and drywall anchors. Install your mantelpiece, then collect some treasures and curios to show off on this special shelf.