Measure Roof Pitch With Speed Square

Mark along the outside edge of the rafter angle square for your angled cut.

Measure roof pitch with speed square.

Pitch multiplier tables make it easy to use a particular pitch to estimate a roof s square footage. Made of steel aluminum or plastic this common carpenter s tool combines a ruler a try square a protractor a line scribing tool a common width board ripping guide and a saw guide for making accurate 90 and 45 cuts with a hand or circular saw. Use the table marked common top cut. 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.

Put the pivot point of the speed square a small hole marked pivot where the straight side of the square meets the side with the lip on it at the top edge of a rafter board. A speed square aka rafter square or triangle square is a measuring multitool. Write down the corresponding pitch multiplier for use in your following calculations. A speed square and level can be used to easily find the pitch of a roof.

Roof pitch is the measurement of a roof s vertical rise divided by its horizontal run. Before miter saws and even since professional carpenters used speed squares as a quick saw guide for cutting 45 and 90 degree angles. If you are measuring by pitch as opposed to angles line up the desired pitch as indicated by the common edge on the same edge as the pivot. Common rafters are the most common type of rafter in construction.

It is often compared to slope but is not exactly the same. Find a common rafter angled with the pitch of the roof. Today we are tackling a big beginner lesson which is common rafter layout and cutting. How to use a rafter angle square for roof pitch.

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. Move the square until the table on one side of the rectangular slot in the square is at the right pitch 5 on the top of the board. 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. 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.