50 SILOS: CONSTRUCTION AND SERVICE 



length, and two headers should be placed between each pair 

 of rafters about equally spaced along the length of the rafter. 

 These headers should be made of 2-inch material, and curved. 

 To determine the curvature of these headers, take a radius 

 equal to the distance from the rafter to the center line of the 

 silo, measured on the line extending at right angles to the 

 rafter at the point where the header is nailed to it. Then 

 lumber should be bent around the silo for a frieze and the 

 sheeting nailed securely to this, thus preventing the cold 

 air from coming in. 



The sheathing is most conveniently made from sound 12- 

 or 14-inch barn boards ripped diagonally. These should be 

 nailed to the headers and to the top of the silo wall, so that 

 only the sheathing boards project from the cornice. By 

 covering this with a good grade of prepared roofing, a good 

 roof is secured. Dormer windows in the roof are quite 

 popular and perhaps add something to the appearance of 

 the roof, but are more expensive than the trap door and do 

 not serve so well. A glazed sash used as a trap door will let 

 in more light than the same sash used as a dormer window. 

 It should be covered with quarter-inch meshed galvanized 

 screen in order to protect it from hail. 



The Chute. In order that the silage may be removed 

 from the silo conveniently, it is essential that a chute or 

 vestibule 3}^ to 4 feet square be built in front of the doors. 

 In case of a wooden silo, the framework of the chute is 

 nailed directly to the silo; in case of masonry, bolts should 

 be placed in the wall so that 2x4's may be bolted to the wall, 

 thus serving to connect the chute to the silo. The wood 

 chute is more common than masonry, but masonry is some- 

 times desired on account of its fire-proof qualities, being 

 more permanent and warmer than the ordinary wood chute. 

 If a monolithic concrete chute is to be attached to a mono- 



