How to Install Crown Molding on Rounded Corners

  • 4 hours
  • Advanced
  • 45
What You'll Need
Crown molding
Miter Saw
Finishing nails
Wood filler
Measuring tape
Sand paper
Paint or stain
Stud finder

Learning how to install crown molding can be a tough job, but when a home displays modern rounded corners it can become an even greater challenge. When remodeling a room or simply building a craft project crown molding can be used to add a decorative touch of elegance to any project, this is a skill that can be used many times over. To add to the crown molding project, this will also show how to go around a 45° wall.

Step 1 - Taking Measurements

The old adage measure twice and cut once is very wise when preparing for the installation of any crown molding. You will first need to measure the walls where you want your moldings installed. Take accurate measurements and be sure to record them correctly.

Step 2 - Cutting Moldings

In cutting your molding you must remember that rounded corners will require an extra piece of molding. Make sure to take this into account when taking your original measurements. Adjust your miter saw to cut at an angle of 22 ½°. Measure the exact length of the angled wall corner to corner. Set a long enough piece of the molding with its flat sections sitting perfectly flat on the table and on the fence respectively. Depending on if you're cutting an inside or an outside corner, cut your angle accordingly at the first end. You can then mark the length you acquired earlier and visually line it up with the blade without the saw running. You can then give a shade more in the length and perform the initial adjustment cut on the middle piece. You will then cut another piece of molding 8 or 10-inches long at the same angle at both ends.

With that done, cut this last piece in half, then re-adjust your miter angle at 45°. Take each one of those pieces and cut the squared end at 45°. Place the middle piece (the 1st one cut) against the wall match the 22 ½° with each of the last pieces you just finished cutting. The middle piece should be a bit long (intentionally so), so shave one end gradually until you get a perfect fit of the 3 pieces together.

The other ends at 45° end up on straight walls and were mitered to match the adjoining molding that will also be mitered, blending them in together as they will be fitted on the walls creating a perfect joint. If you don't have access to a miter saw, the moldings can just as well be cut with a backsaw and miter box, or with a hack saw.

Step 3 - Installing Corner Pieces

Begin in the corner and place your middle piece with its matching piece. They should easily butt together with no gaps. Use your finishing nails and a bead of caulk right along the top of your corner pieces to fit them securely in place. You can then fit the 2nd mitered piece to the other end of the middle piece.

Step 4 - Installing Wall Pieces

Using your stud finder find the studs along the wall, you can mark the studs with your pencil for quick referencing as you go. By nailing your molding into a stud you will ensure that it will securely and safely remain in place for years to come. Starting at your corner pieces with a 45° miter cut, take a straight piece of molding and cut it also at 45° to get a perfect joint with the small piece of molding already installed. Begin to nail the molding in place with a small bead of caulk right along the edge of the molding. Continue this process all around the room.

Step 5 - Cleaning Up the Molding

After each piece of molding is installed you will want to go back over the nail holes with a small amount of wood filler to cover the holes. It is also important to look for any small gaps that can easily be filled with a bead of caulk. Once you have all holes and gaps filled sand down any of the excesses to give yourself a smooth surface.

Step 6 - Finishing Your Work

Once you have a clean smooth surface, simply paint or stain your crown molding to match the other molding in your home. This last step will ensure a finished and beautiful appearance to showcase your hard work. Take a minute to step back and enjoy the finished product.