From About This Project
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. The top of the cornice can even serve as a display shelf for art or collectibles.Cornices are surprisingly easy to build, even the 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.
If this sounds interesting, read on and we’ll show you how to select the materials, assemble the parts and attach the cornice to the wall. We’ll also share design tips to help you match a cornice style to your home’s décor.
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. One site offers custom cornices for $3 to $7.50 per inch! Depending on the style, that’s between $216 and $540 for a cornice for a 6-ft. patio door, plus shipping. Build your own and you can expect to spend about one-fourth of that. The materials for the style we show in the how-to photos add up to about $5.60 per foot, or about $45 per window, plus paint. Usually the materials are cheap, although selecting upscale trim like an elaborate crown molding will drive up the cost. For help selecting styles and materials, see “Designing Your Cornice,” below.
Selecting the Wood
If you plan to paint 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 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.
Using a Compound or Sliding Compound Miter Saw
The best tool for cutting miters on wide boards (1x6s) 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 low as $100, or you can rent one for about $35 per day.
You can predrill 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 useful and far too fun not to own yourself.
How To Build Your Own Window Cornices: Getting Started
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 1x2 that’s screwed to the wall above the opening.
Begin by measuring the curtain and curtain rod for length, depth and width. Measure with the curtains open so you take into account their thickness when 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 trim for the box, 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 1x4 to the miter saw fence through the holes in the back. Remember that the long point of the miter is always 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.
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 1x2 cornice ledger to match the wall before you put it up if you think it’ll show after the window covering is in place.
Designing Your Cornice
Design elements within your home should dictate the wood type, molding style and finish that you select. 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 1x4s, 1x6s or 1x8s. 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 1x6 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 1x4 inside the box flush with the top for a depth of 3-1/2 in. Choose whichever method it takes to clear your curtains.
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 1x4s and 1x6s. 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.
Cornice Options and Buyer's Guide
A. Simple 1x6 Box Technique
Tops that don’t show from below can either lap over or butt against the top of the front board of the box. Further box depth adjustments can be made by using a narrower or wider top board or ripping it to a smaller width.
B: 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 and “pierced” moldings offer another unique look and are widely available at home centers.
C: Fabric Wrapped
Fabric-covered cornices can be built from 3/4-in. plywood, since the wood is hidden. If you’d like to wrap a cornice in wallpaper, build it from poplar or a smoother plywood.
Buyer’s Guide
Our drapes are from Restoration Hardware. Call (877) 747-4671 or visit the company’s Web site: restorationhardware.com.