DEAD LOADS 



30 4-0 50 6O 70 80 9O IOO 



Length of Span of Truss A, Ft- 



FIG. 2. WEIGHT OF ROOF TRUSSES FOR A CAPACITY OF 40 LBS. PER 



SQUARE FOOT. 



The weight of steel roof trusses per square foot of horizontal 

 projection of roof for a capacity, P, of 40 Ibs. per square foot is given 

 in Fig 3. 



It should be noted that W s is the dead load per square foot carried 

 by an interior truss. The actual weight of trusses per square foot of 



horizontal projection for a building with n panels will be W s ~^- 



where end post bent (a), Fig. i, is used, and W s ^ n *" ^ where end 



truss bent (b), Fig. i, is used, assuming that all trusses are made alike. 



Weight of Light Trusses. Formula (i) gives the weight of mill 



building trusses and will usually cover the weight of knee braces and 



ventilator framing. By reducing the minimum thickness of metal and 



