Subdivision 2. Rodent Control Requirements

If the first or ground floor of a business building is constructed of cement, tile, or other material impervious to rodent gnawing and does not have a basement or cellar under the entire floor area which can be satisfactorily rodent-proofed, the Health Officer will require that all actual or potential openings through which rodents may gain entrance, such as those around pipes, wires, or other installations, those caused by defects of any kind and those where the floor and side walls join, shall be properly sealed with cement, mortar, masonry, metal collars, metal flashing of twenty-six (26) gauge or heavier, or any other suitable material as indicated, and that open drains or pipes through which rodents may pass shall be securely capped with perforated iron or other metal having openings not greater than one-half (1/2) inch in diameter;

Whenever rodents are found to be harboring under wooden platforms or secondary wooden floors built over cement floors the Health Officer may require the complete removal of such wooden platforms or floors or that they be lowered to a distance not exceeding one-half (1/2) inch above the cement floor; and,

If the first or ground floors of business buildings are constructed of wood, and do not have basements or cellars extending under their entire area that can be satisfactorily rodent-proofed, the Health Officer may require whichever of the following procedures he deems necessary:

Solid, strong doors constructed of hardwood or metal that fit snugly in their frames and on their thresholds or sills so that rodents can not gain entrance through them and that do not present irregular surfaces or cracks for rodents to gnaw through them may be passed without any treatment, at the discretion of the Health Officer;

Doors in such disrepair or in such a poor condition that they cannot be satisfactorily rodent-proofed are required to be replaced by new ones or repaired to the extent that they can be satisfactorily rodent-stopped and they shall swing smoothly and easily on their hinges;

All doors on the sides and rear of a building that are constructed of soft wood, any doors that show evidence of rodent gnawing or have any irregularities, cracks, or small openings along their lower margin or sides that offer potential sites for rodents to gnaw and doors that have any openings over three-eighths (3/8) inch wide between the door and door sill or threshold are hereby required to be fortified and rodent-proofed by using either metal channels of twenty-four (24) gauge or heavier or to be flashed with twenty-six (26) gauge or heavier metal, as directed by the Health Officer in the following described manner:

Wooden door frames are required to be flashed with twenty-six (26) gauge or heavier metal to the same height as the door flashing whenever there is a crack or other defect between them and their doors that may be utilized by rodents for gnawing through the frame;

Irregularities or defects in wooden door sills are to be corrected by flashing the sills with twenty-four (24) gauge or heavier metal;

Any irregularities or defects in door thresholds constructed of cement or masonry which produce any openings under doors three-eighths (3/8) inch or greater shall be corrected by pointing up with cement, mortar, or other suitable material or by constructing a new threshold of similar material as directed by the Health Officer;

Sliding wooden or metal doors and swinging metal doors that have any spaces greater than three-eighths (3/8) inch wide between them and their sills or thresholds are required to have either rigid or movable sliding strips of twenty (20) gauge metal or equivalent material fastened to their lower margins so that spaces under such doors when closed will not exceed three-eighths (3/8) inch in width;

Mail slits in the lower part of doors that are accessible to rodents shall be fitted with covers that cannot be raised by rodents from the outside;

Other openings in exterior doors used as vents or for other purposes shall be fitted with iron grill work having no openings larger than one-half (1/2) inch in diameter or wire cloth of the same mesh of nineteen (19) gauge or heavier; and,

All exterior doors on the sides and rear of business buildings are required to be kept closed at night and during the day unless protected by screen doors with automatic closing devices.

By covering the opening in the side wall or foundation of the building with wire cloth of nineteen (19) gauge or heavier having a mesh of one-half (1/2) inch of less, which will be securely fastened in place with cement mortar or on a tight fitting frame. If it is necessary to gain entrance to the well for any purpose a frame should be installed that can be easily removed, or the frame may be attached by hinges.

By partially closing the openings in the foundation or wall of the building with masonry and treating the remaining opening as in Subsection (a)(1) of this Section;

In lieu of the above described procedures for the rodent-stoppage of light wells and sidewalk vents the following method may be used in suitable instances: