PLANNING THE SILO 47 



questionable whether or not a pit should be used, as the 

 concrete wall forms a shoulder inside of the staves,causing the 

 silage to draw away from the staves as it settles. Also, there 

 is usually a leakage of air between the staves and the founda- 

 tion. 



The foundation of the stave silo can usually be made 

 most economically by simply digging a trench to the depth of 

 2 or 3 feet. This trench need not be wider than 6 or 8 inches 

 but the foundation should be extended above the ground 8 

 inches or a foot. Usually thin lumber is bent around and 

 secured to stakes set in a circle to make a form; but the 

 stakes must not be driven into the ground until the pit is full 

 of concrete, or the soil will be caved in. 



In case a pit is deemed advisable, the earth should be 

 dug out as soon as the hardening of the concrete will per- 

 mit, as the inner part of the foundation may then be 

 trimmed smooth with a spade and plastered, if desired. 



Whether this pit is excavated or not, the foundation 

 should be reinforced with considerable wire or enough steel 

 rods to be the equivalent of at least a J^-inch rod. The 

 amount of steel necessary for this, of course, depends entirely 

 upon the size of the silo and the distance which the founda- 

 tion projects above the ground. If there is any question as 

 to the quantity to use, the reinforcing table shown for 

 masonry silos should be consulted, using the quantity that 

 is called for in this table. 



Drainage is important and should receive more consider- 

 ation than is usually given in the construction of farm 

 buildings, and especially of masonry silos. Any soil will 

 support a greater load when dry than when wet. This is 

 especially true of clay. The heaving motion of frost is due 

 entirely to the moisture contained in the soil, which expands 

 with an almost irresistible force upon freezing. Therefore, 



