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Carpentry Pro Framer

Creating Wooden Cornice Boards

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by

Taylor Balthazar
in

Creating a wooden cornice board is a rewarding project that combines precision and creativity. By focusing on accurate measurements and careful assembly, you can craft a decorative piece that enhances your window's appeal. With the right tools and attention to detail, this DIY endeavor transforms simple materials into an elegant addition to your home.

Measuring and Cutting Boards

Start by measuring the width of your window plus extra space for the curtain rod. Use a miter saw or circular saw to cut the front and two side pieces at 45-degree angles. Take your time to ensure neat miters for a snug fit. Glue the miters and secure them with one-inch brads.

For the top piece, cut, glue, then nail with 1-1/2 inch brads every six inches. You can let it sit flush or extend it slightly for a shadow-box effect. Keep your level and square handy to avoid any misalignment when assembling and eventually hanging the piece.

A carpenter using a miter saw to cut wood for a cornice board at a 45-degree angle

Assembling the Cornice Box

Lay out your cut pieces and start with the end pieces, building the perimeter with the face board at the front. Apply wood glue along the mitered edges and secure each corner with one-inch brads. Ensure they're flush and aligned.

For the top, apply glue where it will sit flush with the frame's edges. Use 1-1/2 inch brads, spacing them roughly six inches apart. These will hold the top and maintain the cornice's integrity over time.

Step back and check your work. The frame should be square, straight, and solid. Use your level or square to double-check that everything is even, ensuring that hanging your cornice later won't be a hassle.

A partially assembled wooden cornice box with glued mitered corners and brad nails being applied

Attaching Trim and Finishing

Choose a trim style that complements your design. Cut the trim pieces at 45-degree angles for the corners, ensuring tight miters. Apply wood glue and secure the trim with small brad nails.

Fill any gaps or nail holes with wood filler and let it dry completely. Sand the entire piece with fine-grit sandpaper for a smooth finish. Apply primer if painting, or choose a stain that complements your room's decor. Let the finish dry completely before handling the cornice.

A carpenter carefully attaching decorative trim to the front of a wooden cornice board

Mounting the Cornice

  1. Position the cornice over your window and mark the wall for screw placement.
  2. Install a ledger board on the wall, ensuring it's level. This board will provide crucial support for your cornice.
  3. Carefully lift and mount the cornice, aligning it with your marks and resting it on the ledger board.
  4. Secure the cornice to the ledger board with evenly spaced screws.
  5. Give it a gentle shake to ensure stability.

With the installation complete, step back and admire how your DIY project has transformed your living space.

Two people carefully lifting and mounting a finished wooden cornice board above a window

Your completed cornice board adds charm to your room while showcasing your craftsmanship. Enjoy the satisfaction of seeing your hard work elevate your living space.

  1. Elley A. Interior design trends for next year. Textures Interior Design. 2023.
  2. Smith J. DIY Window Treatments: Creating Custom Cornice Boards. Home Improvement Magazine. 2022;45(3):78-82.
  3. Johnson R. Woodworking Techniques for Beginners. Carpenter's Quarterly. 2021;17(2):112-118.