How to Cut a 22.5-Degree Angle

Twenty-two and one-half degree angles are commonly needed when installing moulding or baseboard in your home. While most walls turn at a 90-degree angle, it is not uncommon to have walls that turn at a 45-degree angle in some rooms. To join two pieces of moulding or baseboard at a 45-degree angle, you must cut each piece of wood at a 22.5 degree angle. To quickly and accurately make these cuts, use a mitre saw or mitre box.

Measure the piece of baseboard or moulding and mark the location of the cut.

Place the baseboard or moulding in the centre of the mitre box with the mark aligned with the 22.5-degree slots, which are the slots to the left and right of the 90-degree or straight slot.

Tighten then clamps in the mitre box to secure the moulding or baseboard in position. Follow the instructions included with the mitre box to properly use the clamps.

Insert the handsaw into the 22.5-degree slots on the fences on both sides of the mitre box.

Use long and even strokes with the handsaw to cut the baseboard or moulding at a 22.5-degree angle.

Measure the piece of baseboard or moulding and mark the location of the cut.

Pull the lever at the bottom of the mitre saw out and move it left or right to rotate the entire saw. Use the guide on the bottom of the saw to set the saw to 22.5 degrees.

Lower the blade down to the wood with your finger off of the trigger. Move the wood so that the blade falls slightly on the inside of the line.

Position the baseboard or moulding on the saw table and firmly hold it against the fence, ensuring that your fingers and other body parts are away from the saw blade.

Engage the clamps on the mitre saw, if your saw has them, following the operator's manual for the saw on how to hold the wood in place.

Lower the blade so that it is a few inches above the wood, then squeeze the trigger. Slowly lower the saw down and through the wood. Release the trigger after it completely cuts through the wood.

Raise the blade when it stops spinning.