§ 48-73.   Fire-Resistance Ratings
Fire-Resistance-Rated Assemblies. The required fire-resistance rating of fire-resistance-rated walls, fire
stops, shaft enclosures, partitions and floors shall be maintained. 
Opening Protective. Required opening protective shall be maintained in an operative condition. All fire
and smokestop doors shall be maintained in operable condition. Fire doors and smoke barrier doors
shall not be blocked or obstructed or otherwise made inoperable.