64 
CONCRETE SILOS 
Doors 
The forms for casting the face of the jambs may consist of 2-inch 
planks of a width equal to the distance between the wall forms. Strips of 
2x2-inch material should be nailed to the face of the planks so as to form 
2x2-inch vertical recesses on the inside of the opening. Horizontal slots, to 
accommodate the ladder rounds, will have to be made in the planks at in- 
tervals of 18 inches. All surfaces of wood which will come into contact 
with the concrete should be planed and oiled, which will insure a smooth 
surface and prevent the wood from adhering to the concrete. 
The distance between face of the jambs should be 30 inches and the 
jamb forms rigidly maintained in a vertical position and at proper distance 
apart. 
Spacers consisting of 2x4 's, at intervals of two feet, will hold the 
jamb forms apart rigidly and prevent them from bulging from the pressure 
of the concrete. The vertical jamb forms may be made in sections of 
any convenient length, preferably from six to twelve feet. 
As soon as the silo wall has been brought up to the level of the barn 
floor the vertical wooden frames are placed in position, great care being 
taken to have them absolutely vertical. 
The doors for the continuous doorway may be made of 2-inch plank- 
ing, preferably tongue-and-grooved. The doors should be 34 inches in 
width and 30 inches in height. Five pieces of planking 6 inches 
wide, or 4 pieces 8 inches wide may be used conveniently. A 
^-inch hole is drilled on the vertical center line of each plank to accommo- 
date the bolt and hook by which the door is held to the horizontal reinforc- 
ing across the door opening. The bolts used have a screw eye on the outer 
side to which hangs a hook made of heavy steel wire. 
Non-continuous doors are perhaps easier to build than continuous 
doorways, and if the owners are satis- 
fied that they provide suffi- 
cient room for getting the 
continuous ., , • , i , i 
Doors silage out conveniently, there 
is no objection to their use, 
although on the other hand, they pos- 
sess no great advantage over doors of 
the continuous type. The arguments 
often heard that the non-continuous 
door silo is a stronger type than the 
other, and vice versa, carry little weight, 
as either type may be made sufficiently 
strong. 
Non-continuous doors are often 
put in with a distance of about 23^^ 
feet between them, but the spacing 
may vary to suit the individual owner. 
In all cases the arches between the 
doors must contain an amount of rein- 
» • • 1 J. J J.1 i" 11 0. Non-continuous door, made of double layers 
forcing equivalent to ttie lull amount of flooring with building paper between. 
