Measuring 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.

Measuring roof pitch with speed square.

Although there s isn t any standard pitch of a roof used on all kinds of sloped roofs you can determine the range of pitches by using a roof angle calculator and by considering factors like the local climate and roofing materials. Also measure the length of half of the roof from one side of the ridge beam to the. A speed square aka rafter square or triangle square is a measuring multitool. It is often compared to slope but is not exactly the same.

The triangle shaped square was invented in 1925 by albert swanson to provide a quick accurate method for marking rafters. To calculate the size of the roof you need to measure the size of the roof as if it were flat account for roof pitch calculate square footage and finally determine how many squares of material are required for the roof the calculator above can handle all of this simply enter the length width and pitch and it will determine the size of the roof in squares. 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. Roof pitch is the measurement of a roof s vertical rise divided by its horizontal run.

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. The number of inches that the roof rises vertically for every foot of roof. 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. Find a common rafter angled with the pitch of the roof.

So use a tape measure to find the height of the roof above the top wall of the building. Mark along the outside edge of the rafter angle square for your angled cut. Finding the pitch of a roof is simple with a speed square. Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot.

This is a way of measuring the degree of steepness of the roof. 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. How to use a rafter angle square for roof pitch. 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.