16 FARMERS ' BULLETIN 574. 



strengthen the floor. Floors of one thickness give good satisfaction 

 in the South and in growing houses. Three-quarter-inch mesh wire 

 may be used under wooden or dirt floors to keep out rats. In making 

 concrete or cement floors and walls, select Portland cement of known 

 reputation, which should be kept in a dry place; use clear, coarse, 

 sharp sand or gravel which does not contain over 5 per cent of clay 

 or silt and crushed stone or gravel one-fourth to 2 inches in diameter. 

 The gravel should be screened through a one-fourth-inch mesh wire 

 screen and the coarse particles used as stone, while the material 

 which passes through the screen is sifted through a 40-mesh wire 

 screen in order to separate the sand, and any material which goes 

 through the 40-mesh wire is thrown away. A mixing board with a 

 smooth surface and a box for measuring the sand and gravel are 

 necessary. Spread the sand on the board and add the cement; mix 

 these thoroughly together; add three-fourths of the required amount 

 of water, and then the gravel or stone; mix thoroughly and add 

 water to the dry spots, making the mixture just wet enough to be 

 jellylike. Thorough mixing is very essential, as the mortar should 

 completely coat all particles of tjie mixture. Only enough water 

 should be added so that when the concrete is tamped on laying the 

 water will nicely flush the surface. 



Good concrete mixtures may be made of 1 part (2 bags) cement, 2 

 parts sand, and 4 parts stone or gravel, which will take about 10 

 gallons of water in mixing; or 1 part (2 bags) of cement, 2J parts of 

 sand, and 5 parts of stone or gravel, which is mixed with about 12 J 

 gallons of water. If natural gravel or sand is used withput sifting, 

 make the concrete of 1 part (2 bags) of cement and 4 parts of gravel, 

 mixed with about 10 gallons of water, or of 1 part (2 bags) of cement 

 and 6 parts of gravel with about 12 \ gallons of water. A coating of 

 clear cement or of 1 part cement and 1 part sand maybe added to give 

 a smooth finish to the floor. Most concrete or cement floors are damp 

 and cold and, therefore, must be quite heavily covered with litter. 

 A 4-inch foundation of cinders, broken stone, or gravel, which should 

 be made firm by tamping, may T)e laid as a foundation for the cement 

 floor, making the concrete 2J to 3 inches thick. A layer of tarred 

 building paper, which is lapped and cemented with tar at the seams, 

 may be laid between the stone foundation and the concrete. This 

 construction prevents moisture from coming through the earth and 

 concrete, which makes the floor damp. Cement floors should always 

 be built from 4 to 6 inches above the ground level to insure good 

 water drainage. Concrete floors built on the earth are made from 3 

 to 4 inches thick, which is covered with a layer one-half to 1 inch 

 thick of the finishing coat described above. 



