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.
How to find roof angle with speed square.
Outside of the u s a degree angle is typically used.
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 triangle shaped square was invented in 1925 by albert swanson to provide a quick accurate method for marking rafters.
Speed the job of rafter or angle layout by using our rafter angle square also known as a square.
What is a speed square.
For instance a 7 12 roof pitch means that the roof rises 7 inches for every 12 horizontal inches.
This video is very basic and for beginners.
Holding the level and speed square level locate the measurement on the speed square where it meets the bottom edge of the rafter to find the angle of the roof in degrees.
Johnson s rafter angle square has a handy 6 rule for quick measurements.
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.
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.
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.
In this video i show how to find angles using a speed square.
Roof pitch is a determining factor for cost of the roof as well as the roof area and the type of materials used.
Made from plastic aluminum or steel this multi measuring tool combines a protractor a try square a ruler a.
Although there s isn t any standard pitch of a roof used on all kinds of sloped roofs you can determine the range of pitches by using a roof angle calculator and by considering factors like the local climate and roofing materials.
Before miter saws and even since professional carpenters used speed squares as a quick saw guide for cutting 45 and 90 degree angles.