DAIRYING 67 



658. Making a Cement Floor. A solid foundation is first 

 provided, then concrete is laid on this to a depth of about 4 

 inches and a cement facing of about ^-inch thickness spread 

 over the concrete. 



The concrete is made by mixing two sizes of hard rock with 

 clean sharp sand and Portland cement; the following propor- 

 tions may be used as a guide: 



Crushed rock 57 per cent or 12.7 parts 



Gravel or screenings. . .27 per cent or 6 parts 



Sand 11.5 per cent of 2.5 parts 



Portland Cement 4.5 per cent or 1 part 



After mixing the dry sand, gravel and cement, enough water 

 is added to make the mixture pasty; the thoroughly wet, 

 crushed rock is then added and the whole intimately mixed. 



The floor should be laid in blocks to prevent cracking, and 

 the mixture of stone, sand and cement laid as fast as mixed. 

 The finishing surface made of two parts sand and one part 

 cement is spread over the concrete after this has been pounded 

 sufficiently to bring fine cement to the surface, but before the 

 concrete has set. The finishing surface is smoothed by trowel- 

 ing, then wet with a whitewash brush and pure, dry cement 

 sprinkled over it. The surface is then troweled until smooth 

 and hard. 



In making this concrete, the rocks and gravel should be 

 carefully cleaned from adhering dirt before using in the mix- 

 ture. Any adhering dirt forms a coating over the surface that 

 prevents the cement from firmly sticking the pieces of rock 

 together. 



A proper pitch of the floor to the gutters and drains should 

 be provided for when laying the foundation for the concrete. 



659. If a wooden floor is laid it is a good plan to fill in 

 between the joints with cinders until the flooring rests on the 

 cinders. This will help to preserve the wood from decay. A 

 double floor accumulates moisture and rots out sooner than a 

 single floor. The application of > two coats of boiled oil to the 

 floor before it has been wet will fill the pores of the wood and 



