How To Cut Roof Rafters With A Speed Square

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.

How to cut roof rafters with a speed square.

2 lay out a plumb cut on a rafter. Locate the desired roof pitch on the common top cuts table of. Before miter saws and even since professional carpenters used speed squares as a quick saw guide for cutting 45 and 90 degree angles. Ability to read a tape measure ruler.

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. 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. 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.

The key to accurately cutting the necessary angles is the proper use of a basic carpentry tool the framing square. In this first installment we ll start with roof framing. The roof rafters provide integral structural support to the roof. Before you cut your boards you ll need to measure the width of your building and calculate the exact length of each rafter.

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. Building plans will specify the slope a roof should have. 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. Familiarity with using a speed square.

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