Article 4 — Rat–Proofing

All business buildings and premises shall comply with all of the following rat– proofing requirements, and all other buildings and premises shall comply with such requirements the Health Officer may order when rat–infestation is found. (“Details of Rat–Proofing” incorp. 1–22–1952 by O–5046 N.S.)

Only such rat–proof materials and methods as have been approved by the Health Officer shall be used.

• (“Approved Materials and Methods” incorp. 1–22–1952 by O–5046 N.S.)

• §94.03 Rust–Resisting Materials

Solid sheet metal, expanded metal, and wire cloth specified herein shall have a rust– resisting covering, preferably galvanized.

(“Rust–Resisting Materials” incorp. 1–22–1952 by O–5046 N.S.)

• (a) The exterior walls of basements or cellars shall be constructed of cement or masonry impervious to rats at their junction with the ceiling or floor above, and all actual or potential openings in such walls through which rats may gain entrance from the exterior or pass from one building to another, as from one building to another, as those caused by defects in the wall construction, those around drains, pipes, wires, or other installations, and those of any other nature not used for passage, light, or ventilation, shall be closed with cement mortar, masonry, 26–gauge or heavier metal, or other suitable material approved or directed by the Health Officer.

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San Diego Municipal Code

Chapter 9: Building, Housing and Sign Regulations

(6-2000)

• (b) All open pipes or drains in basements or cellars through which rats may pass shall be capped with a perforated metal cover securely fastened in place, preferably with a hinge, the perforations not being greater than one–half (1/2) inch in diameter.

• (c) All breaks, cracks, or other openings in concrete floors or walls of basements through which rats may pass shall be closed with cement mortar.

• (d) Basements and cellars shall be kept free of all rubbish and debris at all times, and all merchandise or other materials stored therein shall be so kept or piled that they will not provide a place of harborage for rats.

• (e) When floors in existing basements and cellars are constructed partly or entirely of wood, and such wooden floor causes or contributes to a condition of rat–harborage, or rat–infestation, the Health Officer may require that such wood floors shall be completely removed and that they shall be replaced with a concrete floor three (3) inches or more in thickness, or if there is no basement floor the Health Officer may require that a suitable concrete floor shall be installed.

• (“Basements or Cellars” incorp. 1–22–1952 by O–5046 N.S.)

• (a) If the first or ground floors are constructed of concrete, tile, or other material impervious to rat gnawing and do not have basements or cellars under the entire floor area which can be satisfactorily rat–proofed, all actual or potential openings through which rats 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 sidewalks join, shall be properly sealed with cement mortar, masonry, metal collars, metal flashing of 26–gauge or heavier, or any other suitable material approved by the Health Officer as being rat–proof, and all open drains or pipes through which rats may pass shall be securely capped with perforated metal having openings not greater than one–half (1/2) inch in any diameter.

• (b) If the first or ground floors are constructed of wood and do not have basements or cellars extending under their entire area which can be satisfactorily rat–proofed, all actual or potential openings through which rats may gain entrance shall be sealed with 24–gauge or heavier metal, the junction of the floors with the sidewalls shall be flashed with 24–gauge or heavier sheet metal which shall extend six (6) inches or more to the floor and four (4) or more inches upon the sidewalls, and all drains or open pipes through which rats

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(6-2000)

may pass shall be capped with perforated metal having openings not greater than one–half (1/2) inch in any diameter.

• (1) If such buildings with wood first or ground floors are built on piers so that the distance between the ground and the lower surface of the joists is less than eighteen (18) inches above the ground surface, or if the foundation of the building is not impervious to rat gnawing, or if there is a foundation but it does not extend twenty–four (24) inches straight down below the surface of the ground, a concrete curtain wall shall be installed around the entire periphery of the building, which curtain wall shall be at least four (4) inches thick and shall extend twenty– four (24) inches below the surface of the ground, or in lieu thereof the curtain wall shall be constructed in the form of an “L” with the vertical portion eighteen (18) inches or more below the ground surface and the lower reinforced horizontal arm extending outwards eight (8) inches from the vertical section.

• (2) When the first, or ground floor is constructed of wood or partly of wood and partly of concrete or other rat–proof material, and the Health Officer shall find that such wooden portion of such floor is not rat– proof, the Health Officer may require such wooden portion of such floor to be replaced with concrete or other material approved by the Health Officer as being rat–proof.

• (c) Whenever rats are found to be harboring under wooden platforms or secondary wooden floors built over either concrete, wood, or other flooring, the Health Officer may require the rat– proofing or 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 floor.

• (“First or Ground Floors” incorp. 1–22–1952 by O–5046 N.S.)

All doors and door jambs or frames serving as front, side or rear entrances to basements, cellars, ground or first floors, and those on upper floors having exterior stairways, as well as any other doors which may be accessible to rats outside of buildings or between buildings and different business establishments shall comply with the following:

• (a) Solid, strong doors constructed of metal, hardwood, or other material approved by the Health Officer as being resistant to rat gnawing, which fit snugly in their frames and on their thresholds or sills so that rats cannot gain

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San Diego Municipal Code

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(6-2000)

entrance through them and which do not present irregular surfaces or cracks for rats to gnaw through may be passed by the Health Officer without further treatment, but doors which are in such disrepair or in such poor condition that they cannot be satisfactorily rat–proofed shall be replaced by new ones or shall be repaired so as to be satisfactorily rat–stopped, and they shall swing smoothly and easily on their hinges.

• (b) Doors constructed of soft wood or other material not resistant to rat gnawing, doors which show evidence of rat gnawing or have any irregularities, cracks, or small openings along their lower margin or sides and therefore offer potential sites for rats to gnaw, and doors which have any openings over three–eighths (3/8) inch wide anywhere or between the door and door sill or threshold shall be fortified and rat–proofed by using either metal channels of 24–gauge or heavier metal or metal flashing of 26–gauge or heavier metal. After application of either metal channel or flashing the door shall swing or move smoothly without any binding.

• (c) Wooden door frames shall be flashed with 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 which may be utilized by rats for gnawing through the frame.

• (d) Irregularities or defects in wooden door sills shall be corrected by flashing the sills with 24–gauge or heavier metal.

• (e) Irregularities or defects in door thresholds constructed of concrete or masonry which produce openings under doors three– eighths (3/8) inch or greater shall be corrected by pointing up with cement mortar or other suitable rat–proof material approved by the Health Officer or by constructing a new threshold of similar material.

• (f) Sliding wooden or metal doors and swinging metal doors that have a space greater than three–eighths (3/8) inch wide between them and their sills or thresholds shall have either rigid or movable sliding strips of 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.

• (g) Mail slits in the lower part of doors which are accessible to rats shall be fitted with covers which cannot be raised by rats from the outside.

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San Diego Municipal Code

Chapter 9: Building, Housing and Sign Regulations

(6-2000)

• (h) 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 any diameter or with wire cloth of the same mesh 19–gauge or heavier. (“Doors” incorp. 1–22–1952 by O–5046 N.S.)

All windows of business buildings through which rats may gain entrance, including all windows having sills less than thirty (30) inches from the ground, or those which may be accessible to rats from the roof of the same building or adjacent structures, and those which rats may gain entrance to by climbing the walls of the building or by means of vines, trees, wires, pipes, or any other installation, shall be rat– proofed if the windows are open or capable of being opened.

• (a) Windows shall be rat–proofed by covering their entire surface with nineteen (19) gauge or heavier wire cloth having a mesh not greater than one–half (1/2) inch. The wire cloth shall be securely fastened to frames that are to be installed so that they may be readily removed to clean the windows or for other purposes. The edges of the wire cloth along the entire outer margin of wood frames shall be covered with metal strips approximately one (1) inch wide.

• (“Windows” incorp. 1–22–1952 by O–5046 N.S.)

All vents or openings for light or ventilation in the foundation, walls, or roofs of buildings which may be accessible to rats from the ground or other surface of by clinging shall be rat–proofed by the installation of iron grills or 16–gauge or heavier wire cloth or expanded metal of 18 or heavier gauge, all having openings no greater than one–half (1/2) inch in any diameter. The metal may be sealed in place with cement mortar or it may be installed on a tightly fitting wooden or metal frame. If a wood frame is used the edges of the wire cloth or expanded metal shall be covered by strips of metal approximately one (1) inch wide.

(“Vents” incorp. 1–22–1952 by O–5046 N.S.)

Unless closed by a metal grill having no openings greater than one–half (1/2) inch in any diameter, all sidewalk vents and light wells of business buildings shall be rat– proofed by one or more of the following methods:

• (a) by covering the opening in the side wall or foundation of the building with 19–gauge or heavier wire cloth having a mesh not greater than one–half (1/2)

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(6-2000)

inch in any diameter, which shall be securely fastened in place with cement mortar or a tight–fitting frame. If it is deemed necessary to gain entrance to the well for any purpose the frame shall be installed so that it can be easily removed or swung open on hinges.

• (b) By partially closing the opening in the foundation or wall with masonry or similar material and treating the remaining opening as in (a) above.

• (c) In lieu of the above described procedures for the rat– stoppage of light wells and sidewalk vents a rat–proof wire basket may be installed upon written approval of the Director of Public Health.

• (d) If he shall deem it necessary, the Health Officer may require that the bottom and sides of light wells shall be rat–proofed with concrete or masonry, making at least one hole per square foot in the bottom for drainage, not greater than one–half (1/2) inch in diameter. If deemed necessary, the openings of sidewalk vents or light wells may be entirely closed with cement mortar or other material impervious to rats.

• (“Sidewalk Vents and Light or Window Wells” incorp. 1–22–1952 by O–5046 N.S.)

When there is evidence of rats harboring in or entering built–in refrigerators or ice– boxes, all openings used by rats shall be sealed with 26 or heavier gauge metal, and if deemed necessary by the Health Officer, the junction of the ice–boxes with the floor and walls shall be flashed with 24 or heavier gauge metal. If the built–in refrigerators or ice–boxes rest on the surface of the ground the Health Officer may require that curtain walls shall be installed around the periphery in the same manner as those used for imperfect foundations of buildings. (See Sec. 94.05 (b)).

(“Built–In Refrigerators or Ice–Boxes” incorp. 1–22–1952 by O–5046 N.S.)

Meter boxes and other installations sunk into sidewalks or in the ground near buildings from which conduits or pipes pass to buildings shall have their sides and bottom surfaces sealed with cement mortar or other rat–proof material. Drainage shall be provided when necessary by holes not greater than one–half (1/2) inch in any diameter.

(“Meter Boxes, Etc.” incorp. 1–22–1952 by O–5046 N.S.)

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San Diego Municipal Code (6-2000)

Chapter 9: Building, Housing and Sign Regulations

Opening of any type in foundations, walls, and roofs of buildings, such as those caused by defects in construction, those resulting from disrepair or deterioration of the buildings, those around wires, pipes, conduits and any other installation, through which rats may enter a building or gain access to the space between double walls from the exterior, and which are not used for light or ventilation, shall be sealed with 26 or heavier gauge metal used as collars or flashing or with cement mortar, masonry, or any other suitable material approved by the Health Officer as being impervious to rat gnawing.

(“Miscellaneous Openings” incorp. 1–22–1952 by O–5046 N.S.)

Openings of any kind in party walls between business buildings shall be rat–stopped in the same manner as those in walls having a free exterior surface, and when feasible, the walls dividing an establishment in which food is handled, stored, sold, or served from other establishments in the same building shall be rat– stopped in the same manner as exterior walls.

(“Dividing Walls” incorp. 1–22–1952 by O–5046 N.S.)

The walls, bottom, and top of elevator and dumbwaiter shaft shall be constructed and repaired so as to make them rat–proof in the same manner as prescribed for basement walls and exterior walls of buildings.

(“Elevator and Dumbwaiter Shafts” incorp. 1–22–1952 by O–5046 N.S.)

Loading platforms shall be constructed of concrete or other rat– proof material placed on a clean solidly packed fill enclosed by a concrete or other rat–resistant curtain wall as prescribed for imperfect foundations or buildings (See Sec. 94.05 (b) (1) hereof.); provided that open wood or other construction may be used where a clearance of eighteen (18) inches or more exists between the floor joists of the platform and the finished ground level, and the intervening space is kept open on at least three sides and is kept clear of all storage and debris.

(“Loading Platforms” incorp. 1–22–1952 by O–5046 N.S.)

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San Diego Municipal Code (6-2000)

Chapter 9: Building, Housing and Sign Regulations

Sidewalks and ground coverings shall be constructed of concrete, solid, masonry, or other rat–proof material laid directly upon the ground or other clean, solidly–packed fill; provided that open construction may be used where a clearance of eighteen (18) inches or more exists between the floor joists of the elevated sidewalk or ground covering and the finished ground level, and the intervening space is kept open on at least three sides and is kept clear of all storage and debris. When rats burrow under sidewalks or ground coverings, a rat–resistant curtain wall shall be installed as prescribed for imperfect foundations of buildings. (See Sec. 94.05 (b) (1.) (“Sidewalks and Ground Coverings” incorp. 1–22–1952 by O–5046 N.S.)

All outhouses, sheds, barns, garages, and other structures shall be rat–proofed and kept free of rats in the same manner as other buildings, or in lieu thereof they shall be torn down. Chicken houses, rabbit houses or hutches, and the like, shall be separated from other structures by at least six (6) feet, and shall be especially well rat–proofed, and shall have a rat– resistant curtain wall as prescribed for imperfect foundations of buildings (See Sec. 94.05 (b) (1), provided that open construction may be used where a clearance of eighteen (18) inches or more exists between the floor joists and the finished ground level, and the intervening space is kept open on at least three sides and is kept clear of all storage debris, and material which would afford food for rats. Outside storage boxes and lockers shall likewise be elevated at least eighteen (18) inches from the ground. Feed pens, mangers, water troughs, shelving, and so forth shall be of open construction.

(“Outhouses, Storage Boxes, Etc.” incorp. 1–22–1952 by O–5046 N.S.)

Any contractor, public utility, person or individual who makes any alterations or repairs on a building or who installs any wires, conduits, or pipes, or who makes any other installation, or who for any other reason removes existing rat–proofing, and does not restore the rat–proofing in a proper condition as soon as it is practicable, or who makes new openings by which rats may enter buildings from the ground, or by climbing, or burrowing, shall be deemed guilty of a misdemeanor.

(“Removing and Restoring Rat–Proofing” incorp. 1–22–1952 by O–5046 N.S.)

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San Diego Municipal Code

Chapter 9: Building, Housing and Sign Regulations

(4-2018)