Figure Out Pitch Of Roof Speed Square

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.

Figure out pitch of roof speed square. 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. To accurately calculate the area of your roof you must first determine its slope or pitch. A 12 in 12 pitch is a. Roof pitch is the measurement of a roof s vertical rise divided by its horizontal run.

The triangle shaped square was invented in 1925 by albert swanson to provide a quick accurate method for marking rafters. Find the inverse tangent of the pitch to find the angle in degrees. It is often compared to slope but is not exactly the same. 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.

I hear read all too often this misuse and usually ignore it. If a magazine such as finehomebuilding is going to put out an article to teach a topic it should use the proper words and definitions. To convert between american roofing ratios and pitch degrees follow these steps. Before miter saws and even since professional carpenters used speed squares as a quick saw guide for cutting 45 and 90 degree angles.

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. A roof s pitch is determined by how much it rises vertically for every foot it runs horizontally. Check your results with the omni roof pitch calculator. Thus a moderate 6 in 12 roof pitch means that the roof rises 6 inches vertically for every 12 horizontal inches it runs.

A 12 12 pitch roof has a pitch angle of 45. Finding the pitch of a roof is simple with a speed square. After finding out your roof pitch angles you can use the calculator to perform the calculations for you instead of doing them manually. 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.

The roof pitch calculator is a convenient online tool you can use to quickly assess the pitch of your roof to determine the length of rafters you need. Leah s recommended tools for beginner diy ers. Divide the first part of the ratio by 12 to work out the pitch. Marvel at your mathematical.