Grain Systems Bin Accessories PNEG-318 - Manual (Page 9)

2. General Foundation Requirements for GSI Bins
PNEG-318 Concrete Foundation Recommendations for GSI Grain Bins 9
Prepare the Foundation Forms
After scribing the diameter of the foundation, proceed by digging the foundation’s footing. This consists of
a large circular trench dug just inside the foundation line. (Refer to foundation details (frost free pad,
inverted “T” and T-Cap) of corresponding bins and tanks in this manual for necessary information.) Once
the footing has been dug, you are ready to build the forms. It is most important that the form be rigid enough
to hold its shape against the poured concrete. Also, the foundation must be flat. Sloped floors cannot be
used in drying bins. A carpenter’s level placed atop the compass 2 x 4 will enable you to set the top of the
forms to match the top of the center stake.
(See Figure 2B.) Check the form work with a transit to ensure
a uniform elevation for the entire foundation. The foundation should be level within 1/8" on non-stiffened
tanks and 1/4" on stiffened tanks at bin wall perimeter. Stiffened tanks must be shimmed level.
Figure 2B Level the Forms
Alternate Foundation Forms
There are two (2) styles of foundation forms commonly used. The first is the circular form shown in
Figure 2B . The second style of foundation can be made of 2" x 8" boards set into a square with the corners
blocked off to form an octagon. (See Figure 2C on Page 10.) This eight (8) sided form will approximate a
circle and can also be constructed easily.
Carpenter’s level
Footing trench