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of the stair is usually a smooth inclined surface. It is 

 sheeted up like a floor, the sheeting resting on stringers 

 which must be very strongly supported and braced to 

 prevent any possible displacement. Now to form the 

 treads and risers, a horse is made, underneath and 

 against which the concrete is to be flowed on top of the 

 sheeting, which will give the required form of the steps. 

 This horse can be made in several ways, the essential 

 features being that there are suitable pieces for string- 

 ers to give rigidity, and then attached to these string- 

 ers are i-in. pieces the exact size of and held in the 

 exact position of the risers on the stair run. In other 

 words, the horse is so built that if it could be lowered 

 into position on ..top of the stair when finished, its 

 contour would exactly conform to the contour of the 

 treads and risers. But while boards are necessary to 

 form the risers, none are used for the treads, except 

 possibly a few at the very bottom to keep the wet con- 

 crete from flowing out over the riser boards. Be sure 

 that this horse is not only supported well, but is braced 

 strongly from above to prevent the slightest tendency 

 to lift or float. If the stair run is to have a smooth 

 top surface without steps, no horse will be necessary, 

 usually, or any top form, except for a short distance 

 up from the bottom. The concrete if made of the right 

 consistency, rather stiff, will not flow to any extent 

 when it is tamped slightly in place. 



OILING FORMS. 



This is done to prevent concrete adhering to forms, 

 warping, etc.; to preserve the lumber, and secure a 

 better surface on the finished concrete. Soft soap, I 

 part of soap to 4 parts hot water, is good. 



The oils or water resisting preparations commonly 

 used are, crude oil (petroleum), paraffine (refined pe- 

 troleum), asphaltum paint or varnish. 



These must be thinned to the proper consistency as 

 occasion demands and applied to forms, either by dip- 



