Many people go for the manufactured roof rafters, as it requires some skill to make your own rafters. All walls supporting the roof should be level and square. A framing square is made use of for cutting obtuse angles (greater than 90 degrees). The top plumb cut is made at the top and the heel cut is made at the bottom, to make a seat at 90 degrees to sit on the wall. It is better to understand the following for cutting the rafters.
Step 1 - Take Measurements and Draw Layout
Measure the pitch of the rafter as well as the length of the rafter, rafter tail, and overhang.
Step 2 - Mark the Plumb Cut on Boards
Make use of the outside numbers on the shorter side of a framing square. As an example, if the pitch is 7/12, coincide number seven with the inside edge of the board. Adjust the framing square so that number 12 coincides with outer edge of the board. Draw a line to join these number marks for creating a plumb cut.
Step 3 - Mark Heel Cut
Mark the heel cut on the other end of the board. Follow the same steps as for plumb cut, but this time use the longer side of the framing square. After you have marked the first rafter, it can be used as a template for other rafters after cutting.
Step 4 - Cut on the Marking
Use the circular saw for cutting on the markings.