Speed Square Roof Angles

Locate the desired angle on the hypotenuse side of the square.

Speed square roof angles.

The triangle shaped square was invented in 1925 by albert swanson to provide a quick accurate method for marking rafters. 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. The angle of a saw blade will get out of whack slightly over time and through use. In this video i show how to find angles using a speed square.

Lay the lipped fence flat on the shoe and take note if it s not even with the speed square. This video is very basic and for beginners. 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. The speed square was invented in 1925 by albert swanson.

Holding the level and speed square level locate the measurement on the speed square where it meets the bottom edge of the rafter to. Swanson was a carpenter in a small town outside of chicago. Finding the pitch of a roof is simple with a speed square. What is a speed square.

Finding angles with a speed square whether you want to make a nice pitched roof on your kids treehouse or you need a utility ramp for your shed entrance getting the right angle on every side. For example for a 7 12 roof pitch. A speed square and level can be used to easily find the pitch of a roof. The rafter square or speed square does more than mark perpendicular lines.

Before miter saws and even since professional carpenters used speed squares as a quick saw guide for cutting 45 and 90 degree angles. 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. A quick way to check the angles is by using a speed square. 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.