150 CEMENT AND CONCRETE 



To support the forms, drive stakes every 3' or 4'. It 

 is considered good practice to put in alternate sections 

 of the walk, and, after this has set, remove the end 

 form and fill in the section not built. For short pieces 

 of walk, however, this is unnecessary. If it is desired 

 to give the walk a slight slope to one side, this can be 

 done by use of a level and straight-edge, placing one of 

 the 2 x 4's lower than the other 1/4" to V is a good 

 side slope for a walk, and will cause it to shed the water 

 very quickly. To make such a slope on a walk to be 

 4' wide, the form in the direction of the slope will be 

 set V lower than the upper one. 



3) For a one-course walk, nothing leaner than a 1 : 2 : 4 

 mixture should be used ; that is, one part of cement to 

 two parts of sand and four parts of broken stone. Both 

 sand and gravel, or broken stone, should be clean and 

 free from clay or other foreign material. If bank-run 

 materials are used, careful screening to get the proper 

 proportions is necessary. 



4) After measuring the sand required for one batch, 

 spread it out in a thin layer on a water-tight platform; 

 then spread the cement on top of the sand and mix to- 

 gether dry, continually turning until the color is uni- 

 form and mixed together without streaks. The ce- 

 ment and sand is then spread out and the coarse mate- 

 rial placed on top. It is then again mixed and water 

 is added until it is of a quaky or jelly-like consistency. 

 Such a mixture can be quickly spread about in the 

 forms and easily leveled with a strike-board resting 



