(a) Except as may be further limited where specific building lines are established or where street widening is contemplated, the space which may be occupied for a sidewalk vault shall be limited to the space between the street or alley line and a line four and one-half (4-1/2) feet from and parallel to the outer face of the curb to the outside face of the retaining wall of the vault; provided that spurs for sidewalk elevators, coal holes, and chutes shall be constructed so that the outer edge of sidewalk doors and coal holes shall be two (2) feet from the outer face of the curb.
(b) Sidewalk vaults shall be designed to support the live loads specified in OBBC. Walls of sidewalk vaults shall be designed to resist all loads including possible surcharge from fixed or moving loads.
(c) The structural slab or arch forming the roof of the vault shall be not less than four and one-half (4-1/2) inches below the finished surface of the sidewalk, and the sidewalk shall be installed in conformity with the rules and regulations of the Director of Public Service.
(d) No glass light shall be installed in the roof of any sidewalk vault.
(e) Manholes or other openings shall be provided in the roof of a sidewalk vault only when their need is conclusively demonstrated to the satisfaction of the Director of Public Service. Manholes or other opening covers installed in the roof of any sidewalk vault shall be approved type and shall not exceed thirty (30) inches in diameter or, when rectangular, shall not exceed thirty (30) inches along any side; shall be of metal or other approved incombustible material constructed to support the sidewalk loads prescribed by this Building Code and to prevent persons from slipping thereon; shall normally be kept closed; and shall have covers and frames flush with the sidewalk or walk. When covers are removed, the opening shall be properly protected and safeguarded.
(f) When approved by the Director of Public Service under provisions of subsection (e) hereof, gratings not larger than necessary to provide required ventilation may be installed in the roofs of sidewalk vaults.
Such gratings shall be of metal or other approved incombustible material constructed to support the sidewalk loads prescribed by this Building Code; shall be flush with the sidewalk, and shall be arranged so that no hazard will be created thereby. Gratings constructed of iron or steel bars shall have bars spaced not more than seventy-three hundredths (0.73) inch apart, and shall be of an approved nonslip type.
(g) Sidewalk vaults shall be paved as required for cellars and shall be maintained in a dry and sanitary condition.