How To Cut Roof Rafters With A Speed Square

Today we are tackling a big beginner lesson which is common rafter layout and cutting.

How to cut roof rafters with a speed square.

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. The secret to making a good rafter is cutting the proper angle. Building plans will specify the slope a roof should have. Before miter saws and even since professional carpenters used speed squares as a quick saw guide for cutting 45 and 90 degree angles.

2 lay out a plumb cut on a rafter. The key to accurately cutting the necessary angles is the proper use of a basic carpentry tool the framing square. Common rafters are the most common type of rafter in construction. Familiarity with using a speed square.

Locate the desired roof pitch on the common top cuts table of. 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. 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. 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 roof rafters provide integral structural support to the roof. 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. 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. The rafter square or speed square does more than mark perpendicular lines.

The rafter square makes it easier to cut the correct angles for anyone looking to make custom roof trusses.