152 CEMENT AND CONCRETE 



fine sand to the surface, making it very slick. Ordi- 

 narily, this practice is not desirable. 

 The edges of the walk must be finished with the edger 

 to give a rounded corner. To line the walk off into 

 sections, use a straight-edge and groover. This must 

 be done before the concrete has begun to set because it 

 is sometimes necessary to force coarse material farther 

 below the surface to make a good groove. Lay off the 

 walk so that the length of the sections will be about 

 one and one-half times the width; that is, a walk 2' 



FIG. 149. Form for double step. 



wide should be divided into sections 3' long, or a walk 

 3' wide into sections 4-1/2 ' long. 



9) If the walk is built where it is exposed to extreme dry- 

 ing from the sun, it is well to protect it until it has set. 

 The protection may be in the form of moist sand or a 

 tarpaulin of some sort. The hot sun and dry winds 

 will tend to remove the moisture from the concrete 

 and prevent it from hardening. Sprinkle the surface 

 for a week or ten days, after which the walk may be 

 put into use. 



