Use your True Angle Tool and measure the angle that both ceilings make with each other. In our example, that corner angle is 140 deg. From the Compound Miter Chart, Crown Moulding Table or the Excel Program , you can obtain the correct miter and blade tilt for this joint. Continue around the room until completed. You now have the basics and can install crown molding in any room of your house that has a Cathedral Ceiling.
Moulding is the British spelling.