STEEL FRAMEWORK OF BUILDINGS 3 



Minimum Roof Load. The minimum roof load, which 

 will include the dead, snow, and wind loads, shall be taken as 

 follows: 



On roof covering and purlins, 40 Ibs. per sq.ft. 



of superficial area, j 

 On roof trusses, 40 Ibs. per sq.ft. of horizontal area. 



LIVE LOADS 



9. Live Loads on Floors. 



(a) The live loads on floors shall be considered as being uni- 

 form over their entire area and shall be taken, as a minimum, 

 per square foot as follows : 



Dwellings, apartment houses, hotels, 



hospitals 50 Ibs. and up 



Office buildings 60 



Schools, theaters, churches 75 



Ordinary stores, public buildings . . . 100 



Warehouses, factories, armories 200 



When designing flooring, joists, girders, etc., the probability of 

 concentrated loads, such as pianos, safes, machinery, wagons, 

 etc., must be considered and provided for. 



(b) The above live loads, except in warehouses and other 

 buildings exposed to simultaneous loading on all floors, may 

 be reduced for columns as follows: 



Columns supporting roof and top floor, no reduction. 



" next ten floors, a cumulative reduction 

 of 5 per cent for each succeeding 

 floor. 



" " remaining floors, a total reduction 



of 50 per cent. 



10. Crane Loads. The actual weight of the crane, its dimen- 

 sions and its lifting capacity shall be used if obtainable, other- 

 wise the following data for Typical Electrical Traveling Cranes* 

 shall be used: 



* Mr. C. C. Schneider in Trans. Am. Soc. C. E., Vol. 54. 



