This is accomplished by use of the main protractor and two specialty protractor angle guides on the inside of the tool.
How to find the angle of a roof with a speed square.
A quick way to check the angles is by using a speed square.
A roof slope of 4 12 is a 1 6 pitch a 6 12 slope is a 1 4 pitch an 8 12 slope is a 1 3 pitch and so on.
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 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.
Johnson s rafter angle square has a handy 6 rule for quick measurements.
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.
Speed the job of rafter or angle layout by using our rafter angle square also known as a square.
Check out some tips on working with a circular saw.
With one number on our square you can frame a roof or a solar panel support or layout stairs cabinets trim work or many other construction projects.
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.
Lay the lipped fence flat on the shoe and take note if it s not even with the speed square.
The triangle shaped square was invented in 1925 by albert swanson to provide a quick accurate method for marking rafters.
This video is very basic and for beginners.
Measuring pitches part of the speed square s role as a protractor and its original mission as a tool is in quickly finding common and uncommon rafter angles for the pitches on roofs.
The guide directly above the protractor is marked common.
Before miter saws and even since professional carpenters used speed squares as a quick saw guide for cutting 45 and 90 degree angles.
In this video i show how to find angles using a speed square.
Roof slope is expressed as the unit rise over the unit run.
You have a perfect 45 degree angle for easy corners.
What is a speed square.
Finding the pitch of a roof is simple with a speed square.
Made from plastic aluminum or steel this multi measuring tool combines a protractor a try square a ruler a.
The angle of a saw blade will get out of whack slightly over time and through use.
One such case is presented in this article video.
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.
