The most common types of windows are double-hung and hinged (or casement)
windows (Figure 8- 14, page 8-11). All windows consist of two parts, the
frame and the sash.
The double-hung window (Figure 8-14) is made of upper and lower sashes
that slide vertically past one another. Screens can be located on the
outside of a double-hung window without interfering with its operation.
Ventilators and window air conditioners may be placed with the window
nearly closed. However, for full ventilation of a room, only one-half
of the area of the window can be used. Any current of air passing across
its face is lost to the room. Its frame construction and operation are
more involved than that of casement windows.
Casement windows (out-swinging or in-swinging) may be hinged at the
sides, top, or bottom. Casements have the advantage of catching a parallel
breeze and slanting it into a room.
· Out-swinging. The casement window that opens out requires the
window screen to be located on the inside with a device cut into its frame
to operate the casement.
· In-swinging. In-swinging casements, like double-hung windows,
are clear of screens, but they are extremely difficult to make watertight,
particularly against a driving rainstorm.
Window frames are made of four basic parts: the head, the jambs (two),
and the sill. (The sash is the framework that holds the glass in the window.)
Where openings are provided, cut away the studs and for equivalent strength,
double the studs on each side of the opening to form trimmers. Insert
a header at the top. If the opening is wide, the header should also be
doubled and trussed. At the bottom of the opening, insert the rough sill.
In hasty construction, millwork window frames are seldom used. Instead,
simple openings are left in the walls with the stops all nailed to the
stud. The sash may be hinged to the inside or outside of the wall or may
be constructed to slide. The sliding sash with overlapping panes is most
common in Army construction because it requires little installation time.
Sills have a usual slope of 1 to 5 inches so that they shed water quickly.
They are wider than frames, usually extending about 1 1/2 inches beyond
the sheathing. They also form a base for the outside finished casing.
A window is normally composed of an upper and a lower sash. There are
two ordinary types of wood sashes: fixed or movable. Fixed sashes are
removable only with the aid of a carpenter. Movable sashes may slide up
and down in channels in the frame (double-hung), or they may swing in
or out and be hinged at the side (casement type).
Sliding sashes are counterbalanced by sash weights that weigh half as
much as the sash. Sashes are classified as single or divided, according
to the number of pieces of glass (or lights).
A sash may be made of 1 x 3 material with reinforced, rolled plastic
material, which can be cut to any desired size. For hasty construction
of window sashes, perform the following steps:
Step 1. Make two frames with the glass substitute installed on one.
Step 2. Nail the frames together. When the two frames are nailed together,
they should be turned so that the joints are not over each other. This
staggers the joints and strengthens the sash. Do not make the window sash
larger than the available glass substitute. If the sash is too large for
the glass substitute to cover, a muntin may be placed in the sash to hold
the glass substitute; this should be fastened with corrugated metal fasteners.
Where long sashes are made, a muntin should be placed in the center for
added strength. Figure 8-15, page 8-12, shows the window frame and sash
Step 3. Cut the side pieces to a length equal to the height of the sash,
less the width of one piece of material.
Step 4. Cut the top and bottom pieces the same length as the window,
less the width of the material.
Step 5. Fasten at the joints with corrugated metal fasteners.