Must a fire rated hollow metal frame have the hourly rating listed on the label?
No, if a frame bears a recognized label qualifying it as a fire door frame, it may support a 3 hour, a 1-1/2 hour, a 3/4 hour, or a 1/3 hour door. Frames used in masonry walls may be used with a maximum 3 hour fire door, while frames used in drywall walls are intended to be used with a maximum 1-1/2 hour fire door.
