Of all the buildings on the average farm the corncrib is usually in
greatest need of rat proofing. Losses sometimes amounting to a fourth
or a third of the total quantity of corn held over winter have been
known. A survey in a southern State showed an average loss of 5 per
cent of corn in storage; in one case 500 bushels were destroyed in
one crib during one winter. The amount of this loss would have been
sufficient to pay for rat proofing the crib several times over. In
building or remodeling a corncrib; therefore, it is most important that
it be made permanently rat proof. Probably the most satisfactory method
of accomplishing this with the common slat-sided corncrib is entirely
to cover the walls and ceiling on the inside and the wooden floors on
the under side with woven-wire mesh or hardware cloth, two or three
meshes to the inch. A heavy grade of woven wire should be used, 12 or
15 gage, and galvanized after weaving. Painting with a tar or asphaltic
paint increases its durability.
[Illustration: Figure 8.--Suggested construction for corncrib: A,
Section through wall; B, section through door, which is made of
cribbing on vertical battens; the metal band on the wall extends across
the door, but is cut and bent Inward at the edges of the door; C, plan
of door; D, enlarged detail of Jamb at closing side of door]
Another method, and one that is less expensive and quite effective as
long as kept in good repair, is shown in Figure 8. Wire netting should
be carried around the entire crib to a height of 2 feet or more from
the top of the foundation. A strip of galvanized iron 8 inches wide
should be fastened above the wire netting. The joints between the
foundation and netting and between the netting and metal strip must
be tight. As rats are unable to gain a footing on the smooth metal and
can not climb over it, it is unnecessary to use wire netting above the
strip. Care should be taken to join the lengths of metal tightly and to
carry the wire netting and strips of metal across and around both sides
of doors and door jambs. It is also advisable to provide doors with
springs or weights to insure their remaining closed.
[Illustration: B31365
Figure 9.--An inexpensive method of rat proofing a corncrib. It is
supported by glazed tiles capped with galvanized washtubs, which,
though not attractive in appearance, have successfully kept out rats]
If possible the corncrib should have a concrete foundation and floor,
as illustrated. Otherwise it should be elevated on posts or piers
so that it will have a clearance underneath of feet or more. If
the supporting posts or piers are covered with sheet metal, or are
protected at the top with metal collars or disks extending at least 9
inches out from the posts, rats will be kept out of the crib. Old cribs
can often be rat proofed in this manner at little expense. Dish pans
and washtubs make convenient rat guards. (Fig. 9.) It is important
that the area beneath the corncrib be kept clear and that nothing that
the rats can climb be leaned against it.[1]
[1] Plans for a 2,000-bushel corncrib (design No. 521) are available
upon request addressed to the Bureau of Public Roads, U. S. Department
of Agriculture, Washington, D. C.