How To Use A Speed Square For Roof Pitch

This is accomplished by use of the main protractor and two specialty protractor angle guides on the inside of the tool.

How to use a speed square for roof pitch.

Swing the square until you read the desired angle on the board s edge and make your mark. How to measure roof pitch with a speed square. 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. 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.

If the shed is unfinished then simply prop the speed square against the roof framing such as the rafter and repeat the same method. To find the pitch just place the pivot point against the shingles. Use a level and a pencil to make a plumb vertical line on one face of an existing rafter. Use the markings on the square to see where the roof edge lines up with the pitch notations.

Then place a torpedo level on the fat base of the rafter square and adjust the square until the level is level and read the pitch on the side of the rafter square. Place the pivot point on the square against the bottom of the rafter and align the 90 degree angle side of the square with the pencil mark. 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. You can use a speed square to find pitches.