(a) Application of section. For the purpose of obtaining maximum rat stoppage at a minimum cost to the owner or occupant of business buildings, the regulations prescribed in this section are set forth as the minimum requirements for applying rat stoppage to business buildings.
(b) Approval of materials and method of installation. The code enforcement department shall approve all materials used and the method of installation.
(c) Protective coating for metal and wire cloth. Solid sheet metal, expanded metal and wire cloth specified in this section shall have a rust resisting protective coating, preferably galvanized.
(d) Covering of foundation wall ventilator openings. All foundation wall ventilator openings shall be covered for their entire height and width with perforated sheet metal plates of a thickness not less than 18 gauge, or with cast iron grills or grates, or with any other material of sufficient strength and equal rat-resisting properties. The openings herein shall be small enough to prevent the ingress of rats, and in no instance shall be larger than one-half inch.
(e) Covering of other openings in foundation or exterior wall. All foundation and exterior wall openings, excluding those used for the purpose of ventilation, light, doors and windows, such as those openings around pipes, electric cables, conduits, openings due to deteriorated wall, broken masonry or concrete, shall be protected against the ingress of rats by closing such openings with cement mortar, concrete or masonry, or close-fitting sheet metal or suitable size pipe flanges or other material with equal rat-resisting properties, which shall be securely fastened in place.
(f) Requirements as to doors. All exposed edges of the lower eight inches of wooden doors and door jambs, serving as front, rear or side entrances into business buildings from the ground, basement or cellar floors, and other doors accessible to rats, shall be protected against the gnawing of rats by covering such doors and jambs with solid sheet metal of not less than 24 gauge thickness. The same material shall be used on door sills or thresholds, or such door sills or thresholds may be constructed of cement, stone, steel or cast iron. Doors, door jambs and sills of coal chutes and hatchways that are constructed of wood shall be covered with solid sheet metal of 24 gauge or heavier, or they may be replaced with metal chutes of 24 gauge or heavier installed in such a manner as will prevent the ingress of rats. All doors on which metal flashing has been applied shall be properly hinged to provide for free swinging. When closed, doors shall fit snugly so that the maximum clearance between any door, door jamb and sill shall not be greater than three-eighths of an inch. Door jambs and sills constructed of metal, concrete, masonry, stone or cement mortar, or cast iron and steel, when fitting closely to exclude rats, are not required to comply with this subsection.
(g) Requirements as to windows. All windows and other openings for the purpose of light or ventilation located in the side or rear of exterior walls which could afford possible ingress of rats shall be covered for their entire height and width, including frame, with wire cloth of 19 gauge or heavier, having a mesh of not larger than one-half inch. All window and other openings for the purpose of light or ventilation in the exterior walls that may be accessible to rats by way of exposed pipes, wires, conduits and other appurtenances, shall be covered with guards of wire cloth of 19 gauge or heavier, having a mesh of not larger than one-half inch, or in lieu of wire cloth covering, such pipes, wires, conduits and other appurtenances shall be blocked from rat usage by installing sheet metal guards of 24 gauge or heavier. Such guards, when used on horizontal pipes, wires, conduits or other appurtenances, shall be placed in a vertical position, and shall be snugly fitted around the pipe, wire, conduit or other appurtenance. Such guard shall measure not less than 12 inches beyond and on all sides of the pipe, wire, conduit or other appurtenance where the intervening space between the wall and pipe permits, and shall extend 30 inches in an upward direction and 12 inches in a downward direction, and shall be securely fastened to the pipe, wire, conduit or other appurtenance and also the adjacent wall, wherever practicable, so that the guard will remain in a vertical position at all times. Such guards, when used on vertical pipes, wires, conduits or other appurtenances, shall be fitted snugly around the pipe, wire, conduit or other appurtenance, shall be placed in a horizontal position (right angle to pipe, etc.), and shall extend horizontally from the pipe, wire, conduit or other appurtenance for a minimum distance of 12 inches beyond and on all sides of the pipe, wire, conduit or other appurtenance, where the intervening space between pipe and wall permits, and shall be securely fastened to the pipe, wire, conduit or other appurtenance and also to the adjacent wall, wherever practicable, in such a manner that the guard will remain in a horizontal position at all times.
(h) Protection of light wells. Light wells with windows in exterior walls that are located below the outside ground level shall be protected from the ingress of rats by one of the following methods:
(1) Installing over the light wells cast iron or steel grills or steel gratings, or other material of equal strength and rat-resisting properties, with opening in grills or gratings not to exceed one-half inch in shortest dimension.
(2) Installing securely to and completely covering existing metal grills that are broken or have openings larger than one-half inch in shortest dimension or otherwise defective, with expanded metal of 18 gauge or heavier, having openings not greater than one-half inch in shortest dimension, or with 16 gauge or heavier wire cloth with one-half inch mesh.
(3) At the option of the owner, the opening in the wall of the building below the grate may be entirely closed with brick or concrete or partially closed and the remaining open space covered with 19 gauge or heavier wire cloth with mesh not to exceed one-half inch.
(i) Protection of space between floor sill and ground—Where sill is less than 12 inches above ground. Business buildings constructed on piers having wooden floor sills less than 12 inches above the surface of the ground shall have the intervening space between the floor sill and ground protected against the ingress of rats by installing a curtain wall of solid masonry, concrete or other materials of a permanent nature of not less than three inches in thickness and 18 inches in depth below the ground surface with a shelf which is two inches in thickness extending eight inches outward at the base of the curtain wall. This curtain wall and shelf shall be installed around the entire perimeter of the business building and fastened securely to the exterior wall of the building in such a manner as will prevent rats from entering the building. All openings into such curtain wall for ventilation, or other purposes not heretofore mentioned, shall be covered the entire height and depth with 19-gauge galvanized hardware cloth or expanded metal of 24 gauge or heavier with a mesh not to exceed one-half inch. In lieu of the installation of such curtain walls, all ground floors of wood construction may be replaced with concrete of not less than three inches in thickness with the exterior walls protected for a height of seven inches above the concrete floor with masonry, concrete or solid metal of 24 gauge or heavier. Exterior wall protection shall be securely tied into the concrete floor at all points.
(j) Protection of space between floor sill and ground—Where sill is 12 or more inches above ground. Business buildings constructed on piers having wooden floor sills 12 inches or more above the ground level shall have the intervening space between the floor sill and ground protected against the ingress of rats by installing curtain walls in accordance with subsection (i) of this section or by installing solid sheet metal coverage of 24 gauge or heavier snugly around each pipe, cable, wire, conduit or other utility service passing through the wooden ground floor. Such metal coverage shall not be less than eight inches in diameter larger than the diameter of the pipe, cable, wire, conduit or other utility service, and shall be securely fastened to the wooden floor.
(k) Protection of miscellaneous openings. All other openings in wooden ground floors through which rats may gain entrance into double walls or the interior of business buildings, such as openings that may exist in floors and double walls above floor sills, shall be closed with 24 gauge or heavier solid sheet metal or 16 gauge or heavier wire cloth of one-half inch mesh, or with masonry or concrete. Wood frame constructed business buildings having concrete or masonry foundation walls shall have ventilators in foundation walls protected as provided in subsection (d) of this section. All miscellaneous wall openings, doors and windows shall be protected in accordance with this division.
(Prior Code, § 13-33; Ord. of 9-11-1945)