Figure 4-17.-Three types of solid-core doors.
doors with only atop and bottom rail, without horizontal
or vertical muntins, are refereed to as “casement” or
“French doors.” Storm doors are lightly constructed
glazed doors. They are used in conjunction with exterior
doors to improve weather resistance. Combination
doors consist of interchangeable or hinged glass and
screen panels.
Flush Doors
Flush doors are usually made up of thin sheets of
veneer over a core of wood, particle board, or
fiberboard. The veneer faces act as stressed-skin panels
and tend to stabilize the door against warping. The face
veneer may be of ungraded hardwood suitable for a
plain finish or selected hardwood suitable for a natural
finish. The appearance of flush doors maybe enhanced
by the application of plant-on decorative panels. Both
hollow-core and solid-core doors usually have solid
internal rails and stiles so that hinges and other hardware
may be set in solid wood.
Two types of solid wood cores are widely used in
flush-door construction (fig. 4-17). The first type, called
a continuous-block, strip- or wood-stave core, consists
of low-density wood blocks or strips that are glued
together in adjacent vertical rows, with the end joints
staggered. This is the most economical type of solid
core. However, it is subject to excessive expansion and
contraction unless it is sealed with an impervious skin,
such as a plastic laminate.
The second type is the stile-and-rail core, in which
blocks are glued up as panels inside the stiles and rails.
This type of core is highly resistant to warpage and is
more dimensionally stable than the continuous-block
core.
In addition to the solid lumber cores, there are two
types of composition solid cores. Mineral cores (see
fig. 4-17) consist of inert mineral fibers bonded into
rigid panels. The panels are framed within the wood rails
and stiles, resulting in a core that is light in weight and
little affected by moisture. Because of its low density,
this type of door should not be used where sound control
is important.
The other type (not shown) has particleboard,
flakeboard, or waferboard cores, consisting of wood
chips or vegetable fibers mixed with resins or other
binders, formed under heat and pressure into solid
panels. This type of core requires a solid-perimeter
frame. Since particleboard has no grain direction, it
provides exceptional dimensional stability and freedom
from warpage. Because of its low screw-holding ability,
it is usually desirable to install wood blocks in the core
at locations where hardware will be attached.
DOORJAMBS
The doorjamb is the part of the frame that fits inside
the masonry opening or rough frame opening. Jambs
may be wood or metal. The jamb has three parts: the two
side jambs and the head jamb across the top. Exterior
doorjambs have a stop as part of the jamb. The stop is
the portion of the jamb that the face of the door closes
against. The jamb is 1 1/4 inches thick with a 1/2-inch
rabbet serving as a stop.
4-13
