“We are now ready to sheathe the silo; let us begin on the inside. First of all tack tarred building paper to the studding, running the strips up and down and having them catch on every third studding. Avoid all openings or rents in the paper. Having placed the paper take common boards dressed on one side and sheet up to the top of the studding. When this is completed repeat the operation by placing a second layer of boards over the first, breaking joints. Narrow boards are preferable to wide ones for this work, as they will swell without bulging. We have double-boarded the inside of our silo by this operation, and rendered it practically impervious to the air. I see no reason for using anything but common lumber for this purpose, as upon swelling it will close up tight enough to keep out the air. Upon the outside of the studding tack building paper again, as shown at Fig. C in the first illustration. Over this paper place any kind of boards that the fancy of the builder may dictate, as clapboards, shiplap, or drop-siding. It will be seen that our walls are constructed as follows, beginning at the outside: First, siding; second, building paper; third, a dead-air space of 8 or 10 inches; fourth, building paper; fifth, common boards; sixth, common boards. No sawdust, tanbark, or other filling should be used, as a dead-air space is a better non-conductor for our purpose and less expensive than any of these. The partition can be built of narrower studding than those used on the sides of the building, and one thickness of boards used on each side, together with building paper, as in the first instance, is sufficient. To prevent lateral pressure bulging the silo two iron rods should be run through the partition walls joining the sides of the building, placing one about two feet above the partition sill and the other about four feet above that. Half or three-fourths-inch rods with heavy caps at the ends should be sufficient, and are easily put in place before the boards are tacked to the partition.
“Two doorways should be left by cutting out a single studding in each compartment upon the most convenient side. These doorways reach to within three feet of the ground, and should be about seven feet in height. They need not reach to within five feet of the top of the building. The ensilage will settle in the silo several feet, and when the time comes to pass it out through the doorway it takes but little time to dig down two or three feet to the top of the door and make an opening large enough to pass out the upper layer. Fig. 1 shows one of the ways in which a doorway may be made so that it can be boarded up air-tight. Instead of making solid doors hung on hinges I think it is better to use boards that will fit in crossways, making them double thick, and having the inside board even with the inside boarding of the silo, as shown in Fig. 1. Do not make the doorways over 6 or 7 feet in length vertically, as in all cases they weaken the structure. Endeavor to have the inside of the silo smooth and perpendicular from top to bottom, with no jogs or shoulders upon which the ensilage can catch or drag.