FARM STRUCTURES 



471 



Figr. 297. The wall of the Iowa silo. 



The Doorframe. The doorframe is continuous with the 

 crossties, which are at least 42 inches apart. The jambs are 

 simply reinforced concrete beams. The crossties contain 

 reinforced bars of equal strength to the horizontal reinforce- 

 ment in the wall proper, and extend back to each side into 

 the open space in the 

 blocks, to obtain a good 

 grip upon the wall. The 

 blocks containing the bars 

 are completely filled with 

 concrete. The bars across 

 the doorway are covered 

 either by blocks filled with 

 concrete or by concrete 

 alone. 



The Foundation. The 

 foundation for the Iowa 



silo may be of any good masonry construction. It is im- 

 portant that the footings be placed below the frost line. 

 Concrete and hard-burned blocks have been used with equal 

 success. A 16-inch footing and a 6- to 8-inch wall are all that 

 is required. The space inside of the wall may be economic- 

 ally added to the capacity of the silo. The extra expense 

 involved is simply that of throwing out the earth within 

 the foundation walls. 



Floors. Although a floor is not absolutely necessary, 

 it adds much to the convenience of removing and cleaning 

 up the silage at the finish. Four inches of concrete will make 

 an excellent floor. Paving blocks or sidewalk blocks have 

 been used successfully. A few floors have been made by 

 laying the hollow blocks flat and plastering with cement on 

 top. 



