How to Build a Cornice Board - An Easy Window Treatment

Learn How To Build A Cornice Board in this easy DIY Window Treatment Tutorial.

Last month you got a sneak peak of today’s project when I showed you a picture of my daughter’s room. In addition to making her upholstered headboard, I made a cornice board as part of the window treatment. It was super easy and adds a lot to the sophistication to the room.

How To Build A Cornice Board – Supplies Needed:

Sheet or scrap of OSB
1×10 (depending on how tall you want your board to be)
Wood glue
Nails
Short staples
Batting
Fabric
Galvanize Angle Brackets
Metal or Wooden Dowel (optional)
Pole Sockets (optional)

Step 1: Measure For Length of Your Cornice Board

Measure to the outside of your mouldings and determine how long you will want your cornice board to be. Also decide how tall you want it to be. My mouldings are 65” long and I want my cornice board 10” tall.

Cut your OSB to the desired size with a table saw, circular saw, or have it cut at your local Hardware Store for you. I cut mine 68″ x 10″ long to accommodate the 1×10 I will attach and give a little bit of room for the batting and fabric and still have a snug fit.

Step 2: Cut 1×10

Cut your 1×10 to your desired distance from the wall. I cut mine 6 inches. Attach the 1×10 to your OSB by putting down a layer of glue first, letting it dry, and then attach with some small screws/nails or if you have it a nail gun. Repeat on other end.

Step 3: Staple Batting To Cornice Board

Lay out your batting and cut it so that you have plenty to wrap around the sides and ends to staple. I had some left from my Upholstered Headboard that I was able to use. Pull tight and staple Make sure you pay extra attention to the corners so you don’t have a lot of bulk. Be sure to use short staples as long stapes will poke through the OSB because it isn’t very thick.

Step 4: Staple Fabric To Cornice Board

Just like you did with your batting, lay out your fabric with plenty to wrap around the sides and ends to staple. Make sure you pull your fabric tight as you staple. If your fabric has a fabric, you will want to pay attention to make sure it lines up correctly.

How To Build A Cornice Board – Tip

Note: One thing to keep in mind is that depending on your window, people may be able to see the back side of your cornice AND if you are NOT planning on having drapes with your cornice board, you will want to make sure the insides of your side panels are covered as well because they will be visible. I cut my fabric 100″ x 18” and had a separate piece cut that fit just the back side that I stapled on after.

Step 5: Attach pole sockets to your cornice board

If you want an easy way to hang drapes with your cornice board, attach pole sockets to the inside of your cornice board so you can easily slip in a wooden or metal dowel.

Step 6: Attach angle bracket to the wall

Attach your angle brackets to the wall. Secure them with screws into a stud if possible. If not, make sure you use wall anchors. (You want to secure them to the wall first, because there won’t be room to fit a drill in there if you secure them to the cornice board first.) Using screws, attach the brackets to your cornice board to secure the board to the wall. You will need two people for this!

And you are done! I couldn’t believe how easy this project was (since my husband has all of the tools already). The building itself probably took me 20 minutes or so. In fact, it was so easy I made another one for my other daughter.

How To Build A Cornice Board – Finished!

Make sure to PIN THIS IMAGE to your favorite DIY board and go grab your supplies!

If you want to see more pictures of my daughter’s bedrooms, make sure you follow me on Instagram!