How to cut angled corners

When making picture frames, installing cornice or crown moulding, fitting skirting, dado or chair rails, you need to be able to cut angled corners for a professional finish. There are various methods of doing this.

Compound mitre joint
For compound mitre joints, such as those used for fitting cornice, crown moulding or skirting, you need to cut two angles - one at 45-degrees on the face of the board, and one at a 45-degree angle to the back. To do this you can use a compound mitre saw, jigsaw with adjustable base plate, or a mitre box and backsaw. You will find more information here and here on cutting for these types of projects.

Mitre joint
For 45-degree angles on the face, such as those used in making picture frames for mounting moulding or trim onto a flat surface, you will find details here. This joint is done by measuring a 45-degree angle on both ends of a piece of timber and board.

GOOD TO KNOW
A mitre box and backsaw is quick and easy to use for this type of joint. If you use a mitre saw, everything is done for you. When using a jigsaw you will need a set-square to measure and mark if you are using a jigsaw.