bridging is used between the studs. The western
c. Braced Frame. A braced frame (3, fig 2-9)
frame is preferred for one-story structures, since it
is much more rigid than a balloon frame. Exterior
permits both the bearing and nonbearing walls, which
studs extend only between floors and are topped by
are supported by the joist, to settle uniformly.
girts that form a sill for the joists of the succeeding
Typical components of the western frame are the
floor. Girts usually are 4 x 6 inches. With the
following:
exception of studs, braced-frame members are
heavier than those in balloon framing. Sills and
(1) Cross-bracing. Cross-bracing between
corner posts are customarily 4 x 6 inches. Unlike the
joists is required to increase the rigidity of the
studs, corner posts extend from sill to plate. Knee
structures.
braces, usually 2 x 4 inches, are placed diagonally
against each side of the corner posts. Interior
(2) Joists. Joists are laid edgewise to
studding for braced frames is the same as for balloon
support the floor boards.
frame construction.
(3) Rafter. The ribs are run from hip, or
d. Light Roof Truss. The roof truss spans the
ridge, to eaves in the roof.
area between walls. A typical light roof truss is
illustrated in [1], figure 2-10. Observe that only half
Sheathing is generally
of the roof truss is shown and the note "trussed rafter
(4) Sheathing.
applied diagonally to assist in strengthening the
symmetrical about this " is given. This means that
structure.
both halves of the truss are identical and there is no
need to show both halves to present the complete
(5) Sill. Sills are horizontal members that
picture of the truss. Note that the sizes of members
either rest upon or form the foundation of the house.
and bracing details are given. For example, the knee
The sill may be a 4 x 4 or two 2 x 4 pieces spiked
braces for each half of the light truss are made of 2 x
together.
4's and spaced at a maximum of 16 feet. A note on
the drawing instructs you to use 16d nails except
(6) Studs. Studs are upright beams in the
where otherwise noted. One of the exceptions for
framework of a building. Studs are normally 2 x 4
example is the nails designated for the rafter tie
set 16 inches on centers.
which are 20d nails.
(7) Plates. The plate is placed across the
tops of the studs. The plate, which is a 4 x 4 or two 2
2-8.
HEAVY FRAMING
x 4's spiked together, serves as a lower base for the
ends of the roof rafters.
a. Heavy framing, such as used in the
construction of large warehouses, consists of framing
(8) Posts. Posts are members set on end to
members at least 6 inches in dimension (timber
support a wall, girder, or other members of the
construction). Long, unsupported areas between
structure. Corner posts are 4 x 4 inches.
walls are spanned by built-up roof trusses. A typical
heavy roof truss is shown in [2], figure 2-10.
b. Balloon Frame. The balloon frame (2, fig
Observe again that only half of the roof truss is
2-9) is a widely used type of light framing, chiefly
shown and the note "symmetrical about
of truss"
because it is economical. The major difference
is given to indicate that both halves of the truss are
between balloon and braced framing in a multistory
identical. Also note that the size of each member is
building is that in balloon framing the studs run the
given together with the splices required, bracing
full length, from sill to rafters. It is customary for
details, and spacing dimensions. For example, the
second-floor joists to rest on a 1 x 4-inch ribbon that
bottom chord for each half of the heavy truss is made
has been set into the studs. Although a balloon frame
up of two 3 x 12-inch x 9-foot, 4-inch long and two 3
is less rigid than a braced frame, it represents a
x 12-inch x 20-foot-long members connected by 4 x
saving in labor and material and is quite suitable for
12-inch x 2-foot, 4-inch-long filler and two 2 x 12-
two-story structures.
inch x 2-foot, 4-inch splice plates secured by four
bolts. The vertical and diagonal braces are connected
to the top and
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