Why Cope Crown Molding?

When deciding to install crown molding in my house, I did quite a bit of online research before jumping in. There is a lot of good information out there on internet sites as well as YouTube. There were some good videos showing how to cope crown molding. However, I could never quite figure out why. I found out pretty quickly on the very first inside corner I attempted to install. Basically, it's not a perfect world. It was frustrating spending time trying to get to 45 degee pieces to fit together without any gaps. I went ahead and tried coping, and even though there were extra steps, it was much easier fitting the pieces together (especially when working by yourself).

Normally, when installing on an inside corner, these are the steps to follow (assuming you are using a miter saw and cutting 'in position').

1. Use a protractor to measure the inside corner angle (most likely it is 90 degrees).
2. Divide the angle by 2. For a 90 degree angle, you get 45. This is the angle to use for setting your miter saw.
3. For the left piece on the corner, set the miter angle to 45 degrees on the right side. The molding piece you will keep will be to the right of the blade.
4. For the right piece on the corner, set the miter angle to 45 degrees on the left side. The molding piece you will keep will be to the left of the blade.

If you are coping, skip step 3 above. The piece will fit directly into the corner with a straight edge. Cut the right piece the same as in step 4 above. The right piece now needs to be coped. This basically means you will cut the back out in order to have a thin edge on the right piece that will fit neatly against the left piece. Check out the video below to see a demonstration.