MILL CONSTRUCTION BUILDINGS 



venience and economy of carrying on the work on a single floor. Records of 

 certain factories show that the cost of labor is from 5% to 10% less when 

 work is all done on a single floor rather than on several floors." 



A further comparison of the cost of wood, reinforced con- 

 crete and steel buildings is made by Mr. Tyrrell in his book 

 "Engineering of Shops and Factories," as shown by the follow- 

 ing extracts in which A is the greatest cost and G the least : 



"Building types, arranged in order of their relative first cost, are as fol- 

 lows: 



A. Complete steel frame, fire-proofed, with curtain walls 

 and plank floor. 



B. Interior steel frame, fire-proofed, with solid brick walls 

 and plank floor. 



C. Complete steel frame, fire-proofed, with curtain walls 

 and reinforced concrete floors. 



D. Interior steel frame, fire-proofed, with solid brick walls 

 and reinforced concrete floors. 



E. Entire reinforced concrete building. 



F. Part interior steel frame, not fire-proofed, with solid 

 brick walls and wood mill floors. 



G. Entire wood mill construction. 



"In comparing the first cost of buildings in wood mill construction and 

 in reinforced concrete, it will be found that their relative cost varies with 

 the location, size of building and the floor loads to be sustained. In the 

 Southern states, or other regions where timber is abundant and cheap,, wood 

 construction will often cost 25% to 30% less than reinforced concrete, while 

 in districts where wood is scarce, the two types may be nearly equal. The 

 comparison depends also on the size of the building, for large ones have often 

 been found to cost about the same in either material,, and small ones are some- 

 times more expensive by 30, 40 or 50% in reinforced concrete than in wood. 

 The required floor capacity also affects the comparison. Light loads with long 

 spans are cheaper in wood mill construction than in reinforced concrete, the 

 cost of the two types being nearly equal in large buildings with 200 pounds 

 imposed load per square foot, and column spacing of 18 to 20 feet. With 

 loads of 300 to 500 pounds per square foot concrete becomes cheaper, and 

 the saving increases rapidly with greater loads of 1,000 to 1,200 pounds per 

 square foot." 



The following extracts taken from an address delivered be- 

 fore the Portland members of the West Coast Lumbermen's 

 Association by C. J. Hogue, Architect, Portland, Oregon, are 

 of interest since they provide comparative data from that sec- 

 tion of the country. 



"As a result of twelve years' experience in New England I saw reinforced 

 buildings (I am speaking from the standpoint of an engineer), concrete build- 

 ings constructed for within 5 to 15 percent of the cost of mill construction, 

 and structural steel buildings at 10 to 25 percent additional cost. Of course 

 in the cheaper types of wood construction there were more differences than 



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