installing crown molding

Moulding How To


how to crown moldingUsing a combination of mouldings to create a build-up allows for creativity and individual style to show through. Moulding Build-ups are endless. Shown are some common build-ups seen in a few different applications. Create your own designs through your imagination and creativity.
> View the Build-Ups Gallery

Installing Moulding

  • The installation of moulding starts with having the right tools. The following are the most common tools needed for a safe installation of moulding:
    • Miter Box, Miter Saw, or Compound Miter Saw
    • Finishing Nails, Nail Set, and a Hammer or Brad Nailer
    • Wood putty and glue
    • Tape Measure
    • Coping Saw
    • Framing Square
    • Protractor
    • Pen and Paper
    • Utility Knife
    • Ladder
    • Safety Glasses
    • Hearing Protection
  • Start by measuring the length of each wall and be sure to subtract any doors, windows or openings. Add 10% to each wall to allow for mistakes. This will provide the amount of moulding needed for the project. It is also helpful to sketch the room noting dimensions and corners.
  • After purchasing the moulding, determine which piece and wall to start with. Identify what miter cuts will need to be made along with any splicing that may be required. When measuring a piece of moulding which will be mitered, add the width of the moulding to the measurement to allow for the miter cut.
  • Nail the moulding in place with finishing nails leaving the corners to nail at the end once all the moulding is installed. Install the moulding around the entire room and go back to nail the corners. If the moulding ends without running into a wall create a return. A return can be created from a scrap piece of moulding. Cut the proper angle on the one end of the moulding and a 90 degree angle on the other end forming a small triangular piece of moulding. Attach the piece with wood glue and tape until the glue dries.

Useful moulding tips and definitions:

  • Mitering: A basic operation in which an angle is cut across the moulding using a miter box and saw or a compound miter saw. Inside and outside corners, and moulding around windows and doors are usually cut at a 45 degree angle.
  • Coping: Coping is another technique used when butting one moulding against the profile of another. First, set the moulding in the miter box as it is to be installed on the wall – upright against the back plate. Cut the end of the moulding at a 45 degree angle. This cut exposes the profile of the moulding. Following the profile, cut with a coping saw at a 90 degree angle with the face of the moulding. This results in a duplication of the profile pattern which fits over the face of the adjoining moulding.
  • Splice/Scarf: In order to install moulding over large spans, you may have to splice two lengths of moulding together. The moulding is spliced with a vertical seam by placing the two pieces of moulding in the miter box as they will be installed, and mitering them at a 45 degree angle. Gluing the joint before nailing the moulding into place will strengthen the joint.


We recommend staining or painting the moulding before it is installed. Fill any nail holes, repair scratches, dents, or damage by sanding the area and using a non-shrinking filler. Allow the filler to dry and lightly sand these areas to remove any rough spots. The stain or paint may need to be touched up once the moulding has been installed. Be sure to protect the area around the moulding by taping it off.