Whenever the provisions of OBBC or this Building Code require the posting of Certificates of Occupancy, placards or warning or other signs, such certificates, placards and signs shall be firmly affixed, shall remain in the designated places, and shall be readable at all times and, if lost, removed or defaced, shall be immediately replaced by a duplicate. Duplicates of Certificates of Occupancy, and of placards specified in Section 3105.13 and 3105.14 shall be obtained from the Commissioner.