CHAPTER XVII 



DOORWAYS, DOORS, ROOFS, ETC. 



These topics have been dealt with in connection 

 with some of the systems treated, so that in this chapter 

 it is scarcely necessary to do more than take up some 

 general features of these parts of the silo. 



Doorways. Doorways are of two types, known as 

 intermittent and continuous. These doorways are both 

 good, and it is a matter of individual preference as to 

 the one to select, although the separate openings are 

 preferred by a great many silo users. These openings 

 are usually 2 feet wide and 3 feet high, and are spaced 

 about 3 or 4 feet apart. This type of doorway makes a 

 stronger wall, but more difficulty is experienced in 

 removing the silage for feeding than with the con- 

 tinuous door. 



An easily constructed intermittent door form for a 

 solid concrete wall silo is suggested by the Association 

 of Portland Cement Manufacturers as shown in the 

 illustration. Make a frame of 2x6 inch lumber as 

 shown. Then prepare a second frame of 2x2 pieces, and 

 nail it around the first. This will provide an offset or 

 jamb of 2 inches in the concrete, to receive the door 

 from the inside. This form should be made so that it 

 will fit closely between the inside and outside wall 

 forms. 



The method of constructing a form for a continuous 

 door opening is similar to the one for separate open- 

 ings. Two pieces of lumber 2x6 inches are cut 5 feet 

 long. Two holes are then bored through each piece. 



(157) 



