Fire resistant aluminum door frame assembly

A fire resistant aluminum door frame assembly for use in partition wall construction having a door opening therethrough with stud means adjacent opposing vertical sides of the opening, said assembly comprising:

• a header assembly having expansion cavity means at opposite upper portions of the door opening, a channel-shaped aluminum header member extending between the cavity means and screw attached to said partition wall along the upper horizontal side of the door opening, aluminum snap-engageable trim members concealing said screw attachment, said trim members having upper and lower snap-engageable legs engaging upper and lower snap-engageable portions of said header member, the lower snap engageable portion terminating short of opposite ends of the header member, said header member including doorstop means projecting downward from, and extending for substantially the full width of, the header member;
• opposing jamb assemblies disposed along opposing sides of said door opening and extending downwardly from said header assembly below the expansion cavity means said jamb assembly having channel-shaped aluminum jamb members screw attached to said partition wall, aluminum snap-engageable trim members concealing said screw attachment, said trim members having snap-engageable legs engaging snap-engageable portions of said jamb members, said jamb members including doorstop means projecting outward from, and extending for substantially the full height of, the jamb members, and, an engageable longitudinal slot, adjacent said doorstop, having a mortising trim strip engaged therein;
• a strike assembly disposed along one jamb assembly at said engageable slot for accomodation of lockset means of a door member, said strike assembly having an exterior aluminum strike plate member with an opening therethrough permitting entrance of a bolt from a lockset, and further having an interior steel angle member separately screw attached to said jamb member, said steel angle providing retentive engagement for a bolt from a lockset;
• at least one hinge assembly disposed along the opposite jamb assembly at said engageable slot, said hinge assembly having an exterior steel hinge plate screw attached to an interior steel back-up plate, the steel back-up plate being separately screw attached to said jamb member and,
• a door member supported within said door opening by said hinge assembly and having a lockset engaging said strike assembly;
• whereby upon exposure to extreme heat, the door frame assembly accommodates expansion of the header and jamb assembly without buckling, and said strike and hinge assemblies respectively maintain said door support and lockset engagement of the door member, wherein said door frame assembly attains a fire rating.