Abstract: The invention is a prefabricated door assembly for installation in a roughed-in door frame. The assembly includes a pair of vertically extending door jambs having interengaging casings and a header unit spanning the upper ends of the door jambs. The header unit includes a header board or jamb having interengaging horizontal casings. Both horizontal and vertical casings have pin nails protruding from their tongue portions which engage the jambs lightly during transport and installation prior to final nailing in place. The assembly also includes L-shaped brackets affixed to the upper outer corners which join and fasten the vertical and horizontal jambs together. The assembly may be packaged as a kit, which may include hinges, shims and/or shimming hardware.

Abstract: Prefabricated door assembly for installation in a roughed-in door frame, the assembly including a pair of vertically extending door jambs having inter-engaging casings and a header unit spanning the upper ends of the door jambs. The header unit includes a header board having interengaging horizontal casings.The header board also includes, adjacent each of its ends, a transverse recess designed to receive the upper end of each of the jambs, the recess having a slightly outward inclination to place a constant tension on the jambs as they engage the roughed-in door frame. The assembly may also include means for placing a downward pressure on the header board to maintain integrity of the joints.