66 
CONCRETE SILOS 
Constructing Monolithic Silo Walls 
As soon as the foundation has hardened under favorable conditions for 
at least two days the wall forms may be placed in position. Much care should 
be taken to locate them centrally and in such a manner that the sides are 
perpendicular. The 4x4-inch uprights should be carefully put in position 
at this time, being supported on wooden blocks or flat stones. After the 
inner form is in position, but before the outer form is placed, the horizontal 
reinforcing rods for the first three feet of wall should be wired to the ver- 
tical rods which were placed in foundation as previously mentioned. The 
outer forms should then be placed in position and tightened, with the small 
wooden spacers in place. Before placing the concrete, it will be necessary 
to clean off the surface of the foundation and moisten it thoroughly. 
The wall forms, having been previously painted with linseed oil or soft 
soap to prevent sticking, may then be filled with slushy concrete made 
in the proportion of one sack of Portland cement to 2^/^ cubic feet of 
coarse sand, to 4 cubic feet of screened gravel or crushed stone, all of the 
latter being between 34-inch and Ij^-inch in size. 
During the summer 24 hours are usually enough for concrete to harden 
before raising the forms, but in cool weather a longer time will be required. 
If the work be undertaken while there is danger of freezing, the usual cold 
weather precautions must be observed. In such cases the materials should 
be heated, or at least free from frost, and mixed with hot water. The 
Concrete Silo built by W. H. Warford of Geneva, Homemade Concrete Silo of Iowa farmers, C. N. 
at LaFox, Illinois, for John Harvey. Seurle and his son. Cost of material, $86. 
