How To Use Stanley Adjustable Roofing Square

You set the angle on this 12 square by moving the adjustable arm to match the correct reading on the scale and locking it down with a thumbscrew. For rafters made in 2 x 6 s or larger lay the square body flush with the bottom edge of the rafter and mark along top edge of the square body. Rafters made by 2 x 4 s lay a carpenter square body flush with top edge of the rafter and marking the bottom edge of the square body.