Door Installation Interior doors are most often purchased as “pre-hung,” meaning that that the door, hardware and frame are provided and holes and notches for the hardware are ready for installation into the framing rough opening. Door frames are made up of two jambs and a head, together with separate mouldings called doorstops. Stock jambs are made of 19 mm (3⁄4 in. nominal) lumber, cut to widths to suit the thickness of the finished wall and usually shaped at the mill, with doorstops and head cut to size (Figure 168). Frames may also be rabbeted to form the stop, in which case the thickness of the frame is usually increased to 32 mm (11⁄4 in.). If frames come unassembled, attach them with nails or screws at each corner. Use shims (usually wood shingles) between the jamb and rough-opening studs (Figure 169) to align the frame. Place shims at the ends of 168 Interior door frame showing typical connection between jamb and head head dado jamb stop 169 Door frame and trim showing frame blind-nailed under doorstop framing studs wall finish shingle wedge nails (under doorstop) jamb doorstop door thickness casing 5-6 mm (3⁄16 - 1⁄4 in.)