Speed Square Roof Angles

The speed square also called a rafter angle or triangle square is an extremely versatile tool originally intended to help carpenters quickly and accurately mark roof rafters it is a triangle shaped measuring tool that s invaluable for the diyer s tool box.

Speed square roof angles. The triangle shaped square was invented in 1925 by albert swanson to provide a quick accurate method for marking rafters. Holding the level and speed square level locate the measurement on the speed square where it meets the bottom edge of the rafter to. 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. Check out some tips on working with a circular saw.

What is a speed square. The speed square was invented in 1925 by albert swanson. For example for a 7 12 roof pitch. A speed square and level can be used to easily find the pitch of a roof.

As a protractor for easily finding and marking various common angles especially roof rafter pitches and angles for stair stringers the vertical supports on a stairway. A quick way to check the angles is by using a speed square. Lay the lipped fence flat on the shoe and take note if it s not even with the speed square. Made from plastic aluminum or steel this multi measuring tool combines a protractor a try square a ruler a.

Finding the pitch of a roof is simple with a speed square. Because of its compact size it is frequently used as a saw guide when cutting framing members as well as a layout tool for quick 45 and 90 degree cuts. Set the level on the edge of the speed square as shown below then place the heel of the speed square on a rafter or gable edge of the roof. Swanson was a carpenter in a small town outside of chicago.

Locate the desired angle on the hypotenuse side of the square. This video is very basic and for beginners. In this video i show how to find angles using a speed square. Before miter saws and even since professional carpenters used speed squares as a quick saw guide for cutting 45 and 90 degree angles.