The Swanson Little “Blue Book” for Roof and Stairway Layout includes detailed instructions and helpful charts showing how to measure, scribe, make cuts, and more with your Swanson Speed  Square or Big 12 Speed Square. Save time determining the right measurements for your rafters by using the Swanson One-Number Method.  Learn how to use the Layout Bar to measure out-of-square corners as you build stairways. The Blue Book is your number one companion and your key to becoming a true pro with your Speed Square.
The Little-Inch Blue Book-Inch for roof and stairway layout includes detailed instructions on how to use the speed square and big 12-speed square using the "One Number Method" for roof layout