The floor must be graded or sloped so that water will not collect on
it in the winter and so that the manure washings may be caught by the
gutters and run to the water-tight concrete manure pit. (To shape the
gutter, make a mold or template by rounding the corners on the flat
side of a 6-foot length of a 4 by 6-inch timber.) A gentle slope,
toward the low corner, of ¼ of an inch for each foot of length or width
is sufficient. This is secured by the use of a heavy grade stake at
each corner of the floor, a straight edge or a grade line, and a spirit
level.
It is an advantage to have a feeding floor its full thickness above
ground. Make light floors 4 inches and floors subject to heavy loads
6 inches thick. For the forms use 2-inch lumber of a width equal to
the floor thickness. Begin on a low side of the floor. Mark the grade
height on each corner stake and set the forms to a grade cord stretched
from stake to stake. Use only good materials and mix the concrete 1:
2½: 5 according to direction on page 15.