How To Cut Roof Rafters With A Speed Square

The key to accurately cutting the necessary angles is the proper use of a basic carpentry tool the framing square.

How to cut roof rafters with a speed square.

A bevel square can also be set to the plumb cut angle and used to mark the rafter s top overhang and bird s mouth cuts. Before miter saws and even since professional carpenters used speed squares as a quick saw guide for cutting 45 and 90 degree angles. Common rafters are the most common type of rafter in construction. The rafter square makes it easier to cut the correct angles for anyone looking to make custom roof trusses.

The secret to making a good rafter is cutting the proper angle. And the secret to cutting correct rafter angles is the speed square also known as the rafter square which was invented in 1925 by carpenter albert j. If you re framing a gable roof on a new house or building a shed or even a doghouse with a gable roof you ll need to cut a number of roof rafters. In this first installment we ll start with roof framing.

Photo 2 shows how to use the speed square to mark a 33 1 2 degree angle the same as you would need on a rafter tail for a roof with an 8 12 pitch. Ability to read a tape measure ruler. Today we are tackling a big beginner lesson which is common rafter layout and cutting. Locate the desired roof pitch on the common top cuts table of.

Demonstrate the basics on calculating laying out and cutting a common rafter for either a full gable roof or for a shed roof on a porch or small addition. The rafter square or speed square does more than mark perpendicular lines. 2 lay out a plumb cut on a rafter. The roof rafters provide integral structural support to the roof.

This is the first episode of a series that i am making called construction rocks this series will help teach skills useful when building a house.