Custom-build your own wood window cornices for one-fourth the price of store-bought.
Window cornices are a simple, inexpensive way to dramatically enhance any room. They’ll hide ugly drapery rods and add a touch of custom-made detailing that makes an ordinary window or patio door look like something special.
Cornices are surprisingly easy to build, even those elegant ones you see in home magazines. Using off-the-shelf trim from the home center and a compound miter saw, anyone with simple carpentry skills can create a beautiful window or door cornice in just a few hours. The top of the cornice can function as display space for art or collectibles.
Build it yourself and save big bucks: Search the Internet for cornice suppliers and you’ll see that you can save huge money by building your own. Build your own and you can expect to spend about one-fourth that.
Using a compound or sliding compound miter saw: The best tool for cutting miters on wide boards (1×6s) is either a 10-in. compound miter saw or a sliding compound saw. Standard compound saws work like typical miter saws, but the motor and blade tip sideways, making them capable of cutting bevels. A sliding compound miter saw cuts compound angles too, but the motor and blade slide on tracks so it can handle wider stock. Be sure to use a sharp finish-cutting blade in either one. Prices for standard compound miter saws start as little as $100 or you can rent one for about $35 per day.
You can pre-drill and hand-nail most of the project, but an air-powered brad nailer with 1 and 1-1/2 in. brads makes the job much easier. Some of the cheaper ones sell for less than $100, or you can rent one for about $25 per day. (Rent one of the special airless ones and you’ll save the price of renting a compressor.) But for the money, compound miter saws and brad nailers are far too cheap and far too fun not to own them yourself.
Build the basic box, then add the trim: Every cornice begins the same way, with cutting and assembling the three-sided, lidded box. Then you add the trim of your choice and finish the cornice. The cornice is then ready for mounting on the wall by screwing it to a 1×2 that’s screwed to the wall above the opening
Begin by measuring the curtain and valance for length, depth and width Measure with the curtains open so you take into account their thickness when they’re bunched. Add an inch or so to the depth and the width of the curtain rod to make sure the cornice will cover everything.
Miter the ends and front box pieces first. It’s easiest to square up the board, then tilt the miter saw to cut a 45-degree bevel for the first end piece and then square it up to cut the second end. The mitered corners are glued and nailed together with 1-in. brads. Measure the assembly to determine the exact length for the top.
When mitering the box trim, always start by first cutting and mounting an end trim piece, then the long front trim and finally the other end. That way, you’ll be able to check fits and get crisp miters at each corner. Fit each miter, then scribe the length of each piece rather than measuring. It’s faster and much more accurate. It’s best to cut pieces just a tad long so you can shave them down until they fit perfectly. If you’re new to woodworking, it’s nice to have a helper by your side to hold the miters together while you’re scribing lengths or fastening parts.
Cutting crown molding is a little tricky. The trick to cutting perfect crown molding miters is to rest the molding upside down and against the bed and fence while cutting the 45-degree angles. If you cut wide crown molding, you may have to extend the fence height by screwing a length of 1×4 to the miter saw fence through the holes in the back. Remember that the long point of the miter is the top edge. That’ll help you remember which way to angle the saw before cutting. To further eliminate the costly mistake of miscutting an angle, draw a light line while you’re fitting the piece to indicate the proper angle.
Designing your cornice:-
Design elements within your home should dictate the wood type, molding styles and finishes that you select. Match the existing trim or other details in your home. You can expand into something a bit more elaborate, but don’t stray too far. At the home center, you’ll find a molding or some combination of moldings that’ll complement any home style.
Depending on the design, the top either overlaps the sides, sometimes with a routed edge, or is nailed to the top or inside of the box and doesn’t show from below. The tops are best made from 1×4s, 1×6s or 1×8s. There’s no need to cut the tops to width if you choose the right combination of top style and board size. The example we show is a 1×6 nailed on top of the box, which gives an overall inside depth of 4-3/4 in. For the same look but with a shallower box, you could also nail a 1×4 inside the box flush with the top for a depth of 3-1/2 in. Choose whichever method it takes to clear your curtains.
Selecting the wood:
If you plan on painting your cornices, poplar and aspen are good choices for the box materials. They’re stable and relatively cheap, and the grain won’t show through paint. Pine and basswood moldings are usually the least expensive choices for paintable trim.
If you want a stained or natural wood cornice, look for oak, mahogany, cherry, maple and others at home centers. The biggest problem is in finding hardwood moldings other than oak. You may have to special-order them or find a specialty millwork supplier by looking under “Millwork” in the Yellow Pages.
Building mock-ups:
Not sure what style to choose? Here’s a tip. Buy short lengths of different types of trim along with some cheap 1×4 and 1×6. Cut everything to 1-ft. lengths and mock up several different combinations. Just squirt a little wood glue on the pieces and clamp them together for about 10 minutes. Hold the mock-ups over the opening to get a feel for the final look. We actually made about 30 cornice samples before deciding on the final design for the how-to photos and the designs on this page. Of course, the hard part is choosing one of course. We’d love to see what you wound up doing. Feel free to send us photos of your cornices and let us know how the project went.
Finishing:
Fill nail holes and prime before painting. If your cornices have elaborate details like dentil blocking, you’ll get better results with several light coats of spray paint instead of brushing. Finish highly detailed natural and stained wood with spray lacquer, shellac or polyurethane. Prepaint the 1×2 cornice ledger to match the wall before you put it up if you think it’ll show after the window covering is in place.
Simple 1×6 box technique:
Tops that don’t show from below can either lap over (upper photo) or butt against (lower photo) the top of the front board of the box. Further box depth adjustments can be made by using narrower or wider top boards or ripping it to a smaller width.
Overlapping top with routed edge:
Overlapping tops simplify construction and are good to use when the top of the cornice will be seen from above. Use a router to carve a profile on the outer lip of the top before you assemble the cornice. “Stamped” moldings (upper photo) and “pierced” moldings (lower photo) offer another unique look and are widely available at home centers.
