Figure 4-18.-Parts of an exterior doorframe.
Wood jambs are manufactured in two standard
widths: 5 1/4 inches for lath and plaster and 4 1/2 inches
for drywall. Jambs may be easily cut to fit walls of any
thickness. If the jamb is not wide enough, strips of wood
are nailed on the edges to form an extension. Jambs may
also be custom made to accommodate various wall
Standard metal jambs are available for lath and
plaster, concrete block, and brick veneer in 4 3/4-, 5 3/4-,
6 3/4-, and 8 3/4-inch widths. For drywall construction,
the common widths available are 5 1/2 and 5 5/8 inches.
The sill is the bottom member in the doorframe. It
is usually made of oak for wear resistance. When softer
wood is used for the sill, a metal nosing and wear strips
are generally included.
The brick mold or outside casings are designed and
installed to serve as stops for the screen or combination
door. The stops are provided for by the edge of the jamb
and the exterior casing thickness (fig. 4-1 8).
Doorframes can be purchased knocked down
(K. D.) or preassembled with just the exterior casing or
brick mold applied. In some cases, they come
preassembled with the door hung in the opening. When
the doorframe is assembled on the job, nail the side
Figure 4-20.-Thresholds providing weatherproof seats.