MASONRY WALLS 267 



Record, December 22, 1900, as follows: "The slabs used on the roof 

 of the concrete stable built for the Anglo-Swiss Condensed Milk Com- 

 pany, Brooklyn, N. Y., were 4 feet wide and about 15 feet long and 

 were constructed as follows: Each slab has a steel frame with three 

 2 x J4 -inch transverse strips set edgewise at the ends and middle, and 

 connected by longitudinal %-inch rods about 3^ inches apart so as to 

 form a gridiron. The rods are set in staggered holes in the edge of 

 the bars and form a framework over and under which No. 14 trans- 

 verse wires are woven 6 inches apart. The lower surface of the frame 

 is covered with open mesh fine- wire netting, wired around the edges, 

 and the frame is filled with 1:2:4 Portland cement concrete made with 

 very fine broken stone. The slab is 2 inches thick and has offset edges 

 to make scarfed joints which are set with cement mortar. Voids are 

 left in the concrete at the edges of the slabs to permit thin flat steel 

 bars or angle clips to be bolted to the frames, and to be bolted to or 

 locked around the framework. Then the holes are flushed with cement 

 mortar and a Y^ -inch surface coat is plastered over the slabs for the 

 final finish. These slabs have been used for side and partition walls 

 as well as for roof sheathing." 



Masonry Walls. Walls for filling in between the columns of 

 mill buildings are commonly made very light, being usually determined 

 by the clearance and the height. For buildings with 20 to 25 ft. posts, 

 8-inch walls are very commonly used. Where the columns are placed 

 inside of the line of the walls, a greater thickness of wall is used than 

 above; 13 and 1 7-inch walls being quite common. 



The thickness of factory and warehouse walls which support roof 

 trusses is about as given in Table XXII. 



The thickness of the wall may be decreased when pilasters are used 

 to assist in supporting the trusses. 



For detailed information on the construction of brick and stone 

 walls see Baker's Masonry Construction and Kidder's Building Con- 

 struction and Superintendence, Part I. 



