100 A B C OF THE STEEL SQUARE 



avoid making a plan, we take 1-3 pitch. This 

 pitch is 1-3 the width of the building, to point 

 of rafter from wall plate or base. For an 

 example, always use 8, which is 1-3 of 24, on 

 tongues for altitude; 12, % the width of 24, 

 on blade for base. This cuts common rafter. 

 Next is the hip-rafter. It must be understood 

 that the diagonal of 12 and 12 is approximate- 

 ly 17 in framing work, and the hip is the diag- 

 onal of a square added to the rise of roof; 

 therefore we take 8 on the tongue and 17 on 

 the blade; run the same number of times as 

 common rafter which gives the length of hip 

 and plumb and level bevels. 



To cut jack' rafters, divide the number of 

 openings for common rafters. Suppose we have 

 five jacks, with six openings, our common rafter 

 12 feet long, each jack would be 2 feet shorter. 

 The first, next the hip, 10 feet, the second 8 

 feet, third 6 feet, and so on. The top down 

 cut same as down cut for common rafter. For 

 the bevel, cut against hip. Take half the width 

 of building on tongue and length of common 

 rafter on blade, and blade gives the bevel. Now 

 find diagonal of 8 and 12, which is 14 7-16 in. 

 Take this length on blade and 12 on tongue, 

 blade gives bevels- If the hip-rafter is beveled 

 or "backed" to suit jacks, then take height of 



