Measuring Roof Pitch With Speed Square

It is often compared to slope but is not exactly the same.

Measuring roof pitch with speed square.

You can use a speed square to find pitches. A speed square and level can be used to easily find the pitch of a 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. 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.

Measuring pitches part of the speed square s role as a protractor and its original mission as a tool is in quickly finding common and uncommon rafter angles for the pitches on roofs. Then place a torpedo level on the fat base of the rafter square and adjust the square until the level is level. 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. With a torpedo level and a speed square you can pretty accurately gauge the pitch of any roof with a gable end photo 1.

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. The hash marks with corresponding numbers between 1 and 30 refer to the roof s rise angle. Directly below the 6 inch mark on the framing square read the required rafter length 13 42 per foot of run for a 6 inch rise 6 in 12 roof. Roof pitch is the measurement of a roof s vertical rise divided by its horizontal run.

Note the number on the common scale parallel with the 45 degree angle of the square. Roof pitch refers to the measurement of the slope of a roof and you express this as a ratio. You have a perfect 45 degree angle for easy corners. To calculate the required rafter length multiply the total run length half the building width plus the width that the roof is to overhang the house wall by this number 13 42.

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. Place the pivot point against the shingles. This is accomplished by use of the main protractor and two specialty protractor angle guides on the inside of the tool.