How To Find The Angle Of A Roof With A Speed Square

The triangle shaped square was invented in 1925 by albert swanson to provide a quick accurate method for marking rafters.

How to find the angle of a roof with a speed square. Speed the job of rafter or angle layout by using our rafter angle square also known as a square. This is accomplished by use of the main protractor and two specialty protractor angle guides on the inside of the tool. Roof pitch is expressed as the total rise over the total span. Simply brace the lipped side of the speed square against the edge of your board pencil a line up the hypotenuse of the speed square and voilà.

Finding the pitch of a roof is simple with a speed square. Roof slope is expressed as the unit rise over the unit run. What is a speed square. 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.

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. Made from plastic aluminum or steel this multi measuring tool combines a protractor a try square a ruler a. One such case is presented in this article video. The angle of a saw blade will get out of whack slightly over time and through use.

Check out some tips on working with a circular saw. In this video i show how to find angles using a speed square. The guide directly above the protractor is marked common. 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.

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. 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. 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. Johnson s rafter angle square has a handy 6 rule for quick measurements.

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. 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. You have a perfect 45 degree angle for easy corners. 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.