How To Figure Roof Pitch With Speed Square

Before miter saws and even since professional carpenters used speed squares as a quick saw guide for cutting 45 and 90 degree angles.

How to figure roof pitch with speed square.

A speed square and level can be used to easily find the pitch of a roof. To convert between american roofing ratios and pitch degrees follow these steps. You can assess this in two ways either as the roof pitch angles which the rafters make with the horizontal or the proportion between the run and the rise of the roof. Often you express roof pitch as the ratio between the rise and the run in the form of x 12.

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. A 12 12 pitch roof has a pitch angle of 45. Check your results with the omni roof pitch calculator. Roof pitch is the measurement of a roof s vertical rise divided by its horizontal run.

Divide the first part of the ratio by 12 to work out the pitch. 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. In the united states a run of 12 inches 1 foot is used and pitch is measured as the rise of the roof over 12 inches. The triangle shaped square was invented in 1925 by albert swanson to provide a quick accurate method for marking rafters.

Roof pitch refers to the amount of rise a roof has compared to the horizontal measurement of the roof called the run. It is often compared to slope but is not exactly the same. Marvel at your mathematical. Roof pitch refers to the slope which the rafter creates.

Find the inverse tangent of the pitch to find the angle in degrees.