How To: Use a framing square

Tim Carter of Ask the Builder demonstrates the basics of a framing square. Tim shows how to make the marks for a simple roof rafter.

A simple tool like a framing square can help with laying out cuts for building a swing set or play house. The framing square is good for making sure things are cut square. But it can do much more. If you have to make a plumb cut or a seat cut, the framing square will assist you.

There are a lot of numbers on a framing square. The numbers that go from 1 to 16 on the smaller arm relate to the pitch or slope of the roof. As the roof gets steeper, the numbers get higher. To get from the framing square to the piece of wood your are cutting, work with the numbers on just one side of the square. Either the outside numbers or the inside numbers. Don't confuse them.

For example, if you want a 7/12 pitch roof, hold the 7 on the outside edge of the framing square on the piece of lumber. On the other leg of the square, align the 12 with the other side of the lumber. Mark the lumber and make your cuts. It is that simple to get the proper cuts for your roof.