A cornice board is an inexpensive and easy-to-make window treatment for your home. A cornice board is simply a 4-sided wooden box. There is no bottom, and the wall forms the back of the box. Think of a cornice board as a wooden valance with a top.
Cornice boards can be upholstered with fabric, painted, or, most easily, covered with a wallpaper border. With just a few basic carpentry tools, you can build your own custom-made cornice boards in just one day.
Materials Needed:
The materials needed to construct your own window cornice board are quite inexpensive. A lower-quality sheet of plywood is fine since the cornice board will be covered with wallpaper and the finish will not show. Some construction sites might even have scrap plywood available at no cost. Look for sales on wallpaper and paint.
Materials Needed for Cornice Board
- 1/4 to 1/2 inch thick Plywood
- Wood Glue
- Small Finishing Nails
- Sand Paper
- Small Can of Paint, Foam Paintbrush
- 7-inch-wide Roll Wallpaper Border
- “L” Brackets
Directions
Cutting and assembling the pieces of wood you will use to build your cornice board are fairly simple and require common tools found in many homes. Your local hardware store might be able to cut the pieces for you at a nominal charge.
Measure and Cut Wood
- Front Piece
Measure the width of the window from outside edges; add 4 inches to the width. Cut wood to this length. The width of the wood should be the same width as your wallpaper border. This will be the front face of your cornice board.
- Top Piece
The length of the top piece (shelf) of your cornice board should be the same as the front piece. The width should be 1/4 to 1/2 inch less than the 4 inches, depending on the thickness of your plywood.
- Side Pieces
The side pieces should extend 4 inches out from the wall.
Assemble the Pieces
- Using a thin bead of glue, attach the top piece to the front. Using small finishing nails, nail pieces together. (See second picture, above.)
- Attach side pieces to the front and top, again using a thin bead of glue and finishing nails.
- Countersink the nails into wood using a nail set, if desired, for a smoother finish.
Finishing
After the glue has dried you are ready to finish your cornice board. Sandpaper, paint, and a wall paper border are all that are needed. You will hang the finished cornice board with “L” brackets, available at any hardware store.
Sand the Cornice Board
Using a medium-fine grade sandpaper, go over the entire cornice board to smooth any rough edges. (See first picture, above.) Pay particular attention to where the sides join the front piece; you should gently curve the joint so the wallpaper will lay smoothly on the wood.
Paint the Cornice Board
Using a color similar or complimentary to the wallpaper, paint the bottom edge of the front piece of wood and the inside of the side pieces. (See second picture, above. In this picture, we used an off-white paint.) Let the paint dry.
Wallpapering the Cornice Board
Now it’s time to add wallpaper to your cornice board.
Hanging the Cornice Board
“L” brackets are used to hang the cornice board to the wall. Be careful to avoid the window casing when positioning the brackets. (See the third picture, above, of “L” bracket.) Using two brackets (three for a long window) attach brackets to wall about 1 to 2 inches above the window. (You want to cover the window covering’s hardware.) Attach one brackets about 1/3 of the window length from the left and one 1/3 of the length from the right. (If using 3 brackets, attach one bracket in the middle.)Set the finished cornice board on the brackets, and attach the top of the “L” brackets to the underside of the top piece of wood.
This picture (see above, third picture) is shot looking upward from the blinds to the bottom of the cornice board. The “L” brackets are attached to the bottom side of the top piece of the cornice board. After attaching with the “L” brackets, the cornice board will be firmly attached to the wall and the top can be used as a shelf to hold plants, knickknacks, or whatever you desire.