343 



ESTIMATE OF WEIGHT AND COST 



TABLE XXVI. 

 WEIGHTS AND PER CENTS OF DETAILS OF MILL BUILDINGS. 



Channel eave struts were used in all except the third building in which 

 4-angle laced struts were used. A very good idea of the per cent of 

 details in the different parts of the structures can be obtained from 

 Table XXVI. The details of riveted mill building trusses will commonly 

 vary between the limits of 25 and 35 per cent as given in the table; 

 being more often near 25 than 35 per cent. The per cents of details in 

 trusses is practically independent of the length of span, and is larger for 

 light than for heavy work. It should be noted that the details in 

 columns is mostly due to the bases and connections the per cents of 

 details will therefore decrease as the length of the column increases. 

 The weights of the other parts are so variable that no general rules can 

 be given. Where a uniform per cent is added to the total weight of 

 main members to provide for details, it is common to add about 30 



