All openings in roofs for the admission of light or air, other than those provided for in §§ 5-25-660 and 5-25-680, shall have incombustible frames and sash glazed with wired glass, but ordinary glass may be used if protected above and below by galvanized steel wire screens with a mesh not exceeding one inch and the wire not smaller than No. 12 gauge. The top screen shall be installed as specified in § 5-25-850.