How to Install Crown Molding (Prepping, Coping, and Final Touches)

The corner where a wall meets a ceiling is a lonely place.  So when we decided to prepare the nursery for our baby girl and finish (finally!) our boys’ rooms we knew that the list of upgrades had to include crown molding. These rooms are relatively small and mostly square so they weren’t huge projects to start with. And now that I’ve tweaked my process I can share it with you and use it to trim out larger and more complex rooms in our home.

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Depending on the size of the room you will want to allow yourself a day to complete this job. This includes enough time to purchase the material, paint the crown molding (before installing), get it installed, and do paint touch-ups. What tools are required? Glad you asked.

Tools required:

  1. Miter Saw
  2. Brad Nailer
  3. Cordless drill
  4. Tape Measure
  5. Caulking Gun

Preparing for Crown Molding

Typical house construction can make it difficult to drive a nail through crown molding and into something substantial that can bear the molding’s weight. And nothing ruins your day like a piece of crown molding falling on your head.

If you have a finish nailer that can drive 3″ nails, you can use that. A 3″ nail in the center of the crown molding will penetrate the two horizontal pieces of lumber that frame out the top of the wall.  However, if you are like me and only have a brad nailer with a 2″ capacity you have to get a little creative.

To make sure that there would be something sturdy to drive nails into, I first cut many small triangular wedges out of a 2×4 that could be screwed into the wall and would provide a nice solid piece that even a short 1″ nail could penetrate.

To make sure they were cut to the correct angle, I carefully positioned a scrap of the crown molding on the 2×4, then traced the flat edge from the back of the molding onto the board.

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From there, I set it on the miter saw and adjusted its angle until it met up evenly with the line.

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I cut enough to place one at each end of the wall and at 2 ft intervals along the wall. For an 11×11 bedroom, this worked out to about 6 or 7 per wall, or 24-28 per room. That’s a lot of cuts, but I made a mark on the miter saw fence to help me quickly position the 2×4 each time. The whole process actually went really quickly. After cutting all of the blocks, each one was screwed to the wall with 3″ screws.

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Installing the First Pieces

After all the molding had been pre-painted and allowed to dry, the first pieces could be installed. I prefer to cope crown molding (and base molding too for that matter), since it makes fitting pieces together at inside corners so much easier than when mitering. When coping any molding, whether it’s base or crown, the piece on one side of the joint is cut straight, while the piece on the other side of the joint is cut to match the profile of the molding. So in this room, since it is square, two of the pieces were cut straight, while the other two were profiled or “coped” to fit in between the first two. Still with me?

When I planned how to install the crown molding, I knew I needed to consider the location of the door. I wanted to install the pieces so that when someone entered the room they would not be looking directly at a coped joint. It was almost guaranteed that some of my coped joints would be less than perfect and I might use a little extra caulking to fill the gaps, so it would be less noticeable if it’s not the first thing to be seen when walking in the door. For us (and likely for you, if your rooms are square), this meant that the pieces of molding with straight cuts would be installed on the same wall as the door and the wall directly across.

The actual installation was pretty straightforward:

  1. Measure the length of the wall
  2. Cut your molding to this dimension on the miter saw
  3. Position the cut piece of molding in place
  4. Nail through the molding into the triangular blocks at A FEW (3-4) places near the center of the wall

DO NOT go nuts and nail the trim all the way along the length of the wall. Keeping the ends free will allow you to adjust the fit of the coped joint.

Believe me, I understand the intense thrill that comes from driving 20-30 brad nails in under 10 seconds. But you have to wait.  You’ll thank me later.

How to Cope Crown Molding

I will admit that it coping trim is a little more work than mitering a joint. But it’s hard to argue with results, so I have all but abandoned mitered joints on inside corners.

It’s really not that complicated either. The basic steps are as follows with more details below:

  1. Measure the distance from the insides of the previously installed pieces of trim
  2. Mark your molding at this dimension and make 45 degree cuts on a miter saw
  3. Outline the edge where the miter cut meets the existing face of the trim
  4. Use a coping saw to cut as close to this line as possible
  5. Clean up the edge with a rasp
  6. Check the fit and trim if necessary

Since crown molding is “thicker” at the top than at the bottom, I always measure from the top of one piece to the top of the other for consistency. Also, I add 1/16” to 1/8” or so to the measurement for a nice tight fit. Once I have this measurement, I mark it on my piece of molding and cut it at 45 degrees on the miter saw. I cut the molding upside down in the miter saw so that I can hold it against the fence at the proper angle to miter it. Again, because the molding is “thicker” at the top, the top of the coped piece will be shorter than the bottom. This helps me remember which direction to cut the angle.

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The only reason for making the 45 degree cut is to mark the profile of the molding so that it can be coped with a hand saw. To make the profile stand out even more, I use a pencil to trace the edge where the painted surface meets the raw wood.

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Next, I used a coping saw to cut as close to this edge as I can without cutting the painted surface. Coping saws take a little bit of practice to master, so I would recommend practicing on a few scrap pieces first. Keep in mind that crown molding will hang on the wall at an angle, so don’t cut with the coping saw perpendicular to the back face. I try to keep the coping saw parallel to the face that will butt up against the ceiling.

I check the fit of my cuts against a piece of scrap molding and fine tune with the coping saw or a rasp (basically a file for wood) if necessary (it usually is). Once the cutting and tuning is complete, the coped end looks like this:

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Now that these cuts are complete, I add a little wood glue to the ends of the coped pieces, position the molding in place, and nail it into the triangular blocks on the wall. Again, I start with a few nails in the center and check how things are fitting before nailing it for good. If for some reason the coped joint does not fit tightly in the corner, I use a shim to close up the gap between the pieces. I nail everything in place for good once I’m happy with how everything is fitting.

Finishing Touches

To finish off the installation, I run a bead of paintable caulking along the edges where the molding meets the ceiling and the wall. I also caulk the joints in the corners and fill the nail holes. After that it’s time for a quick coat of paint over the caulking.

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We love the way this crown molding makes the rooms look so much more finished. Hopefully you have learned a thing or two about the process. If so, please Pin or Share to pass the word along!

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