UNIVERSAL PORTLAND CEMENT CO. 
65 
Wooden Form for non-continuous doorway. 
Doors 
of horizontal reinforcing put 
around the silo. Thus, if the 
doors are 3 feet in height, with a 
distance of feet between 
them, the horizontal reinforcing 
in the space between the doors 
should be equivalent in amount 
to that placed in 5}^ feet of the 
wall where there are no doors. 
t;;^^/. *c" I II'? On this page is shown a form 
for a non-continuous door open- 
ing. The bottom and 
Form'and pieces are made 
Frame 2x6-inch plank cut 
to the arc of a circle 
with diameter the same as the 
outer diameter of the silo wall. 
The two sides are made of 2x4 's. 
A frame of lighter material is 
placed aroimd the outside of the 
form for the purpose of making 
a recess two inches deep around 
the opening on the inner side of 
the wall, into which the door will 
fit. This frame is tapered to 
permit removal from the wall as soon as the concrete has hardened. 
It may then be used again for the next doorway above. 
If desired, a door frame of small angle iron may be used to protect the 
corners of the concrete. The frame should be slipped on over the form, and 
both frame and form then placed in position. The angle iron should be 
cut a few inches longer than the dimensions of the opening and the ends 
embedded in the concrete. The frame should also be anchored to the 
concrete by large spikes. Holes to receive the spikes should be drilled 
in the angles, 12 inches apart. The spikes should be bent at right 
angles to secure a better hold in the wall. 
The doors may best be made of two thicknesses of lx6-inch matched 
flooring with a layer of tar paper between. The lx6-inch boards are held 
together by two lx4-inch cleats across the top and bottom, and 
one 2x4-inch cleat across the center. The middle cleat is made 
larger than the others in order to take care of the strain caused by the large 
bolt in the center. A 2x4, 40 inches long, or a similar piece of material, 
is placed on the bolt, making a large "button" by which the door is held 
to the wall. The door is clearly shown on the opposite page. 
One thing should be remembered by the farmer, the rural contractor 
and others who are constructing silos — that door jambs and the doors be so 
constructed that there is no exposed surface of steel against the silage. 
This is one reason why concrete jambs have been constructed, and are 
recommended as the best form of construction. 
