(a) All windows and other openings for the purpose of light or ventilation, located within 30 inches above the existing ground or roof level immediately below such openings, shall be covered, if necessary, for their entire height and width, including frames, with wire cloth of 19 gauge or heavier, having a mesh of not larger than one-half inch.
(b) All windows and other openings for the purpose of light or ventilation in the exterior walls, which 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, wire, conduits and other appurtenances shall be blocked from rat usage by installing sheet metal guards as provided in the following section.
(1964 Code, § 19-359)