440 ESTIMATES OF STRUCTURAL STEEL. CHAP. XIII 



wire netting, No. 19, costs 25 to 30 cts. per square of 100 sq. ft. Brass wire, No. 20, costs about 20 

 cts. per Ib. No. 9 galvanized wire costs about 3 cts. per Ib. For trimmings, flashing, ridge roll, 

 etc., add I ct. per Ib. to the base price of corrugated steel. 



Tar and Gravel Roofing. Four- or five-ply tar and gravel roofing, for average conditions, 

 costs from $3.75 to $4.00 per square, not including sheathing. Five hundred squares of 5-ply 

 tar and gravel roofing, in 1912, in the middle west, cost $3.93 per square, not including sheathing. 



Tin Roofing. Tin roofing costs from $7.00 to $9.00 per square, not including sheathing. 



Slate Roofing. Slate roofing costs from $7.00 to $i2.oo.per square, not including sheathing. 



Tile Roofing. The cost of tile roofing is variable, depending upon style of roof and location 

 and local conditions, and may vary from $13.00 to $30.00 per square, not including sheathing. 



WINDOWS. Windows with wooden frames and sash, and double strength glass, will cost 

 from 25 to 50 cts. per sq. ft. of opening. Windows with metal frames and sash and wire glass, 

 will cost from 45 to 55 cts. per sq. ft. of opening. 



SKYLIGHTS. Skylights with metal frames and sash and wire glass, will cost from 50 to 

 60 cts. per sq. ft. Skylights made of translucent fabric stretched on wooden frames, will cost 

 from 25 to 30 cts. per sq. ft. Louvres without frames, will cost about 25 cts. per sq. ft. 



CIRCULAR VENTILATORS. Circular ventilators will cost about as follows: 12-in., 

 $2.00; i8-in., $6.75; 24-in., $10.00; 36-in., $15.00 each, when ordered in lots of at least six. 



ROLLING STEEL SHUTTERS. Rolling steel shutters will cost $0.75 to $1.00 per sq. ft. 



WATERPROOFING. The following cos.ts for waterproofing engineering structures are 

 taken from the Proceedings of the American Railway Engineering Association, Vol. 12, 1911. 



(1) Bridge floor, 6-ply felt and pitch, \z\ cts. per sq. ft., including protection over waterproofing. 



(2) Trough bridge floor, 4-ply burlap and asphalt, 10 to 165 cts. per sq. ft. (3) Bridge floor, 3-ply 

 burlap and asphalt, and asphalt mastic, 16 cts. per sq. ft. (4) Concrete slab bridge floor, 5-ply 

 felt, i-ply burlap and pitch, 15^ cts. per sq. ft., including a 10 year guarantee. 



MISCELLANEOUS MATERIALS. The following prices are for small lots, f.o.b. Pittsburgh 

 (May, 1914). 



Chain. Standard chain, YS m -> 7 1 cts. per Ib.; f in., 3 cts. per Ib.; I in., 2.6 cts. per Ib. 

 For BB chain, add if cts. per Ib., and for BBB chain, add 2 cts. per Ib. 



Nails. Base price of nails, $2.00 per keg of 100 Ib. 2od to 60 d nails are base; for xod to 

 i6d, add 5 cts. per keg; for 8d and gd, add 10 cts. per keg; for 6d and 7d, add 20 cts. per keg; 

 for 4d and 5d, add 30 cts. per keg; for 3d, add 45 cts. per keg, and for 2d, add 70 cts. per keg. 



Gas Pipe. Gas pipe costs about as follows: Standard gas pipe I in. diam., black, 3 cts. 

 per ft., glavanized, 5 cts. per ft.; 2 in. diam., black, "]\ cts. per ft., galvanized, n cts. per ft.; 3 in. 

 diam., black, 165 cts. per ft., galvanized, 23 cts. per ft. 



Steel Railroad Rails. Bessemer rails, $28 per gross ton (2240 Ib.); open-hearth, $30 per 

 gross ton. 



Wire Rope. The cost of steel wire rope is about as follows: f in. rope, 10 cts. per lineal ft.; 

 | in. rope, 13 cts. per lineal ft.; I in. rope, 20 cts. per lineal ft.; if in. rope, 45 cts. per lineal ft. 



Manila Rope. Manila rope costs about 12 \ cts. per Ib. Sisal rope costs about 9 cts. per Ib. 



HARDWARE AND MACHINISTS SUPPLIES. Prices of hardware and machinists 

 supplies are for the most part quoted by giving a discount from standard list prices. The " Iron 

 Age Standard Hardware Lists," price $2.00, may be obtained from the Iron Age Book Department, 

 239, W. 39th St., New York. Discounts from these standard lists are given each week in Iron 

 Age. The base prices of structural materials are given in the first issue of each month of Engineer- 

 ing News, and are given in each issue of Iron Age. 



REFERENCES. For detailed estimates of steel mill buildings and additional data on the 

 cost of steel mill buildings see the authors " The Design of Steel Mill Buildings." For detailed 

 estimates of steel highway bridges and additional data on the cost of steel highway bridges, see 

 the author's " The Design of Highway Bridges." For data on the cost of retaining walls, bins and 

 grain elevators, see the author's " The Design of Walls, Bins and Grain Elevators." For data 

 on the cost of steel head frames, coal tipples, and other mine structures, see the author's " The 

 Design of Mine Structures." 



