How To Use A Speed Square For Roof Pitch

Use a level and a pencil to make a plumb vertical line on one face of an existing rafter.

How to use a speed square for roof pitch.

Use the markings on the square to see where the roof edge lines up with the pitch notations. You can use a speed square to find pitches. 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. 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.

Simply move the pivot point against the edge of your board lining up the edge of the board with your desired angle. To find the pitch just place the pivot point against the shingles. You can use the speed square to mark an angle such as when cutting a rafter tail by holding the pivot point against the board. This is accomplished by use of the main protractor and two specialty protractor angle guides on the inside of the tool.

How to measure roof pitch with a speed square. Swing the square until you read the desired angle on the board s edge and make your mark. You have a perfect 45 degree angle for easy corners. 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.