Any grain elevator building or ice house may be constructed of wood if the exterior walls and roof are covered by an envelope of incombustible material and if the first story walls of grain elevators are built of masonry not less than 20 inches thick or reinforced concrete not less than 12 inches thick. The structure above the first story shall be anchored to such wall with 3/4 inch bolts embedded not less than two feet in the masonry or concrete and spaced not more than two feet in the masonry or concrete and spaced not more than six feet apart. Each corner of the structure shall be further reinforced with iron rods not less than one inch thick in diameter extending from above the roof plate to and into the first story wall to a depth of not less than 60 inches. The roof plates shall be fastened down with nuts and washers. All window frames and sashes in the super structure shall be of metal. The openings shall be protected by wire grating of number 14 gauge, with meshes not exceeding 1/2 inch. The openings in the body of the building and in the engine house shall have suitable metal shutters.
('72 Code, § 151.024) Penalty, see § 10.99