106 STEEL OFFICE BUILDINGS. CHAP. II. 



girders which require to be grouted, shall be supported exactly at the proper level by means of 

 steel wedges. Structural steel and ironwork shall be set accurately to the established lines and 

 levels. The steel and iron must be plumb and level before riveting is commenced and must be 

 kept in position until final completion. Temporary bracing shall be provided to resist the stresses 

 due to derricks and other erection equipment. Elevator shafts shall be plumbed from top to 

 bottom with piano wire. Riveted connections shall be carefully drawn up before riveting is 

 commenced. Not less than one-third the holes shall be filled with field bolts, drawn up tight. 

 All field connections shall be riveted. Pneumatic hammers shall be used in driving field rivets. 

 Rivets must have a sufficient length to completely fill the holes and to form full heads. Rivets 

 must be tight with full concentric heads. Loose or imperfect rivets must be cut out and redriven, 

 recupping or calking will not be permitted. Holes which will not admit a cold rivet must be 

 reamed. Where bolts are permitted, washers not less than in. thick shall be used under the 

 nuts, the nuts shall be drawn tight and the threads checked with a chisel. Connections to cast 

 iron and for separators in steel beams may be bolted. 



REFERENCES. For the details of the design of tall buildings the following books may be 

 consulted: Kidder's "Architects and Builders Pocketbook"; Freitag's "Fire Prevention and 

 Fire Protection"; Freitag's "Architectural Engineering"; Ketchum's "The Pesign of Steel Mill 

 Buildings." 



For a full discussion of foundations for steel office buildings, see Jacoby and Davis, " Founda- 

 tions of Bridges and Buildings," published by McGraw-Hill Book Co. 



