Speed Square Roof Pitch

You have a perfect 45 degree angle for easy corners.

Speed square roof pitch.

A speed square will have two specialty protractor angle guides on the inside of the tool which has both common rafter angles and hip valley angles marked out. And it can be used to mark any angle between 0 and 90 degrees across a board s face. It can be used to make lines perpendicular square to a board s edge. Now divide the rise by the multiplier to get the pitch eg.

The key is a protractor function that identifies the common and rare roof pitches. Swing the square until you read the desired angle on the board s edge and make your mark. Then place a torpedo level on the fat base of the rafter square and adjust the square until the level is level and read the pitch on the side of the rafter square. To find the pitch just place the pivot point against the shingles.

48 10 4 8. The triangle shaped square was invented in 1925 by albert swanson to provide a quick accurate method for marking rafters. There are many other ways the speed square can be used but i will focus on these two in this tutorial. Finding the pitch of a roof is simple with a speed square.

The pitch of this roof is 4 8 12. You can use a speed square to find pitches. As a matter of fact finding the pitch of a roof was the motivating factor for how this tool was invented in the first place hence it s official name the rafter square. A speed square is a tool that just about every carpenter will have in her bag.

The best rating speed is quite expensive which quickly begins to get any roof. You can also use a speed square to find level if you re on the job without a spirit level. Constructing a new shed roof at the desired pitch is as easy as knowing how to use a speed square. Therefore if your roof rises 4 inches over the course of 12 inches of horizontal run then your roof pitch is 4 12.

Since pitch is the rise over a 12 inch run divide the run by 12 to get the multiplier in this case 120 12 10. 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. The calculator above can handle much of this math. Common roof pitches set as grow inches over a twelve inch run.

The swanson speed square is a popular tool with most carpenters.