Level of Difficulty: Intermediate Do-It-Yourselfer – Moderate
Completion Time: Week-end

Crown moulding is used to provide elegance to the transition point between wall and ceiling. Adding both texture and character to a room, crown moulding also acts as a decorative border to your décor. There are many styles and patterns to choose from.

Installing crown moulding takes patience and considerable skill; the moulding is positioned at an angle on the wall, and each joint is made up of compound angles. By following our step-by-step instructions, any determined DIY can install crown moulding with professional-quality results.

Another option to consider for easier installation: mitreless crown moulding with corner blocks.

TOOLS

  • Mitre saw or Mitre box with saw
  • Mitre saw cutting supports, or Saw horses
  • Caulking gun
  • Hammer or Power nailing gun

  • Tape Measure
  • Stud finder
  • Level
  • Coping saw
  • Round file
  • Square

MATERIALS

  • Crown moulding
  • Wall panel adhesive
  • Paintable caulking
  • Finishing nails, or Power brad nailer
BEFORE ASSEMBLY

NOTES

MEASURING AND QUANTITIES
Taking measurements is an essential step in determining the quantity of mouldings required and the exact length of each piece.

Calculate the length of each wall using a tape measure. Add 12" to 24" for each wall to account for losses resulting from angle cuts. If there are obstructions that prevent you from installing mouldings, don’t forget to subtract them from the total length.

For aesthetic reasons, opt for long mouldings. For example, in the case of a 14' wall, use a 16' moulding rather than two 8' mouldings. You will reduce the number of joints and enhance the look of your mouldings.

CUTTING
Crown moulding can be made from vinyl, painted wood or medium density fibreboard (MDF). They can be 16’ long, so it is important to set up supports at the height of the mitre saw to hold the mouldings in place. These could be sawhorses built up to height or adjustable supports with rollers.

Set up the mitre saw in a well-ventilated area outside the room to avoid dust.

Use a good-quality finishing blade with a minimum of 40 teeth, though 80 teeth is preferable since the more teeth a blade has, the cleaner the cut.

INSTALLATION
Before you start, allow the crown mouldings to acclimatize for 24 to 48 hours in the room where they will be installed.

You can paint or stain your crown mouldings in advance. You will simply need to touch them up a bit after, and cover the nail heads you’ve concealed with wood filler. This actually simplifies the job, because you won’t need to do any masking.

Crown mouldings can be fastened with finishing nails or a power nailer. Never use nails longer than 2" as you might hit a wire; 1 ½" nails are perfect for the job. For a cleaner, more professional job, use a brad power nailer. Pre-drill your nail holes so that mouldings do not split. Use a drill bit of a smaller size than the nails.

On a long wall, shorter pieces can maintain the look of continuity by mitering the joints rather than having them butt together.

STEPS
The spring angle is the angle from the wall to the back of your crown. In most cases, it is 45°.

1.1. Cut a small piece of crown moulding off the end of a long piece and place it against the fence of the mitre saw with the finished side out. Remember to have the long side of the pattern facing down.

1.2. Mark the saw fence and table with a permanent marker. This will act as a cutting guide for the spring angle.

1.3. Place supports so that the ends of the crown moulding will be secure when cutting.

2.1. Measure from the saw fence to the ink mark on the saw table and cut a scrap piece of wood with this measurement.

2.2. Place the wood against the ceiling and make a pencil mark below it. This is called the “witness mark” and will give the lower edge of the crown moulding. Continue around the room.

2.3. Use a level to verify that the marks are level and adjust accordingly.

2.4. Measure the walls from corner to corner and mark the distance on the top of each wall to 1/32". If the piece is longer than 10' add 1/16".

2.5. Mark the the location of the studs just below the witness mark. One way of doing this is to start the tape in the corner and put a mark every 16" on both walls from the corners. Use a stud finder for greater accuracy. In many cases, the studs can be found by looking at the bottom of the walls, as most drywallers leave a narrow space above the floor.

MEASURE AND PREPARE THE INSTALLATION

The first piece of crown moulding will be squared on each end.

3.1. Place the squared end of the first piece in the corner and tack into place with a finishing nail. This will hold the piece up for either measuring the second piece or cutting off the end to fit a door or window moulding.

3.2. Cut the first piece to the dimensions written earlier on top of the wall.

3.3. Push both corners in place and then flex to get into place. Be sure to align on the witness marks.

3.4. Nail bottom with 8d finishing nails or a brad power nailer over the stud marks on the wall. Repeat on the ceiling. Leave 2' un-nailed on each end.

CUT AND INSTALL THE FIRST PIECE FOR WALL #1

Work counter-clockwise so that only one end of a piece has to be coped.

4.1. Lay the second piece along the wall below the first. This piece should be longer than the space.

4.2. Draw a pencil line along the second moulding to the angle of the first piece.

4.3. Mitre along the pencil line or at 45° going in the same direction.

4.4. Trace the edge of the mitre with a pen to make it more visible and cut the excess at a slight angle along the line with a coping saw. This is called a coped joint.

4.5. Adjust and fit the coped joint to the first moulding with a round file if needed. Square-cut the other end so it butts into the corner.

4.6. Nail bottom into the studs with 8d finishing nails or a brad power nailer over the stud marks on the wall. Repeat on the ceiling. Leave 2' un-nailed on each end.

COPE THE SECOND PIECE FOR WALL #2

COPE THE SECOND PIECE FOR WALL #2

For a long wall, two pieces may have to be spliced together. This is called a scarf joint.

5.1. Position both mouldings, as they will be on the wall.

5.2. Find the nearest stud before the intended splice point and mark.

5.3. Cope the end of the moulding that will butt against the wall on your right. Make sure it is longer than needed for the splice.

5.4. Measure ¾" past the stud intended for the scarf joint and mark the other end of the piece.

5.5. Set the saw for a 45° angle and cut.

5.6. Nail the piece to the wall and ceiling.

5.7. Measure the second piece up to the backside bevel of the first piece. This is the shortest or ceiling side of the first cut.

5.8. Cut the second crown moulding.

5.9. Measure back and cut the other end square

5.10. Push the two angled ends together and nail the scarf joint first before pushing the squared end into place.

5.11. Measure, cut, cope and position the crown moulding for the last wall. Both ends will have to be coped as the end of the Wall #1 is squared, like the end of the Wall #3.

SPLICE TWO MOULDINGS

6.1. Place a square on the corner to check the angle. If the angle is not square, use a protractor.

6.2. Set the coped end in the inside corner and mark the outside corner piece.

6.3. Set the saw to 45° to cut the outside corner from the mark out. This will form the point of the outside corner.

6.4. Check the angle with a protractor and mark a scrap piece. Outside corners are marked and mitered.

6.5. Re-set the saw in the other direction with the change in angle and cut the scrap piece. Put it together with the right-hand side to re-check the angle. Adjust if the angle is not also 45°

6.6. Cut the left piece using the scrap as a template.

6.7. Nail the piece into place.

CUT THE OUTSIDE CORNER

7.1. If the crown mouldings were previously painted, simply touch up where needed.

7.2. Fill small cracks in the corners and between the moulding and wall with a paintable caulking. Wipe off excess with a damp cloth.

7.3. Lightly sand the surface with fine sandpaper.

7.4. Apply a primer and then paint.