70 



STEEL OFFICE BUILDINGS. 



CHAP. II. 



For details and data on fireproofing and fireproofing materials, see Freitag's "Fire Prevention 

 and Fire Protection," and Kidder's "Architects and Builders Pocket Book." 



LOADS. The loads coming on office buildings may be grouped under the following headings: 

 (i) dead loads; (2) live loads; (3) wind loads; (4) snow loads; (5) miscellaneous loads. 



Dead Load. The "dead load" includes the weight of the structure, and other permanent 

 fixtures and machines. A formula for the weight of roof trusses is given in Chapter I. The 

 weights of materials are given in Table I. The actual weights of all dead loads should be calcu- 

 lated. The minimum weight of a fireproof floor should be taken at not less than 75 Ib. per sq. ft. 

 of floor surface. In office buildings a minimum of 10 Ib. per sq. ft. should be added for movable 

 partitions. 



WEIGHT OF STEEL IN TALL BUILDINGS. The weight of the steel framework for tall 

 steel buildings varies with the height, the column spacing, the floor loads and other conditions. 

 The weights of steel per cubic foot for several tall steel buildings are given in Table II. In calcu- 

 lating the weight per cubic foot only the part of the building above the curb was considered. 



TABLE II. 

 WEIGHT OF STEEL IN TALL BUILDINGS, POUNDS PER CUBIC FOOT. 



Live Loads. The live loads on floors are commonly given in pounds per square foot. The 

 minimum live loads in pounds per square foot as required by the buildings laws of several cities 

 are given in Table III. 



Mr. C. C. Schneider, M. Am. Soc. C. E., in his "General Specifications for Structural Work of 

 Buildings" gives the following requirements for live loads on floors. 



"Table IV gives the 'live' load on floors, to be assumed for different classes of buildings. 

 These loads consist of: (a) A uniform load per square foot of floor area; (b) A concentrated 

 load which shall be applied to any point of the floor; (c) A uniform load per linear foot for girders. 

 The maximum result is to be used in calculations. The specified concentrated loads shall also 

 apply to the floor construction between the beams for a length of 5 ft." 



