International Fire Code 2903.4: Agricultural Products. Hay, straw or
similar agricultural products shall not be stored adjacent to structures
of combustible materials. Storage shall be limited to stacks of 100 tons
(91 metric tons) each. Stacks shall be separated by a minimum of 20 feet
(6096 mm) of clear space. Quantities of hay, straw and other
agricultural products shall not be limited where stored in or near farm
structures located outside closely built areas. A permit shall not be
required for agricultural storage.

