Every nitrocellulose products room shall have an enclosure of two-hour fire-resistive construction, if it has a floor area of 1,000 square feet or less and of three- hour fire-resistive construction of solid masonry or concrete if it has a floor area exceeding 1,000 square feet but not more than 2,000 square feet; and of four- hour fire-resistive construction if it has a floor area exceeding 2,000 square feet; provided, however, that these requirements shall not apply to a standard fireproof vault intended for any of the purposes of such a room.
(Prior code § 92-75)