In business buildings constructed on piers having wooden floor sills greater than 18 inches above the ground level, solid sheet metal coverage of 24 gauge or heavier may be installed snugly around each pipe, cable, wire, conduit or other utility service passing through wooden ground floor in lieu of curtain walls. The diameter of such metal coverage shall not be less than eight inches larger than the diameter of pipe, cable, wire, conduit or other utility service, and shall be securely fastened to the wooden floor. 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 concrete or masonry. The intervening space between the ground and the floor sill shall be kept clean and clear. If the distance from the top of the floor sill to the under surface of a wooden floor is less than 18 inches, rat-stoppage treatment, as provided in other sections of this article, shall be used.
(1964 Code, § 19-363)