STEEL PLATE FLOORING 



297 



buckled plates are covered with concrete, which is given a finishing coat 

 of cement or is covered with plank flooring. 



Steel Plate Flooring. Fireproof floors around smelters, etc., are 

 often made of steel plates. Flat steel plates do not make a very satis- 

 factory floor for the reasons that the plates will bulge up in the cen- 

 ter when fastened around the edges, and because they become danger- 

 ously smooth. 



Neverslip Wrought Steel Floor Plates are made from 24" x 72" to 36" 

 x 120", and from 3-16" to i" thick. These plates are designed to take 

 the place of the cast iron checkered plates formerly used for floors, 

 weigh about 50 per cent less and last much longer. The stock sizes, 

 weights and safe loads for Neverslip floor plates are given in the Stock 

 List of the Scully Steel Co., Chicago. These lists are issued about six 

 times a year and will be sent free upon request. 



Thickness of Timber Flooring. The thickness of white pine 

 and spruce flooring for different spans and loads is given in Table 

 XXXIIIa. The following fibre stresses were used in calculating the 

 thickness : Transverse bending, 1000 Ib. ; end bearing, 1000 Ib. ; bear- 

 ing across the fibre, 200 Ib. ; shear along the fibre, 100 Ib. 



TABLE XXXIIIa. 

 THICKNESS OF SPRUCE AND WHITE PINE PLANK FOR FLOORS. 



For yellow pine use nine-tenths of the above thicknesses. 



