Figure 1-57.—Expansion joint.
(fig. 1-53). Friction-tight insulation is installed by
placing the batts (bundles of insulating material)
between the studs on the exterior walls. Studs are spaced
12, 16, or 24 inches OC as specified in the blueprints.
Corner and Casing Beads
Standard wallboard corner bead is manufactured
from galvanized steel with perforated flanges, as shown
in figure 1-54. It provides a protective reinforcement
of straight corners. The corner bead is made with l-inch
by 1-inch flanges for 3/8- or 1/2-jnch single-
layer wallboard; 1 inch by 1 1/4 inches for 1/2-inch
or 5/8-inch single-layer wallboard; 1 1/4 inches by
1 1/4 inches for two-layer wallboard application. It is
available in 10-foot lengths.
Multiflex tape bead consists of two continuous
metal strips on the undersurface of 2 1/8-inch-wide
reinforcing tape (fig. 1-55). This protects corners
formed at any angle. Multiflex tape bead comes in
100-foot rolls.
Casing and trim beads (examples are shown in fig.
1-56) are used as edge protection and trim around
window and door openings and as moldings at ceiling
angles. They are made from galvanized steel in three
styles to fit 3/8-inch, 1/2-inch, and 5/8-inch wallboard
and come in 10-foot lengths.
Expansion Joints
Expansion joints are vinyl extrusions used as
control joints in drywall partitions and ceilings. A typical
form is shown in figure 1-57.
Figure 1-58 shows a typical metal frame layout and
use of corner and casing beads for corners, partition
intersections, and partition ends. It also shows a typical
Figure 1-58.—Metal frame layout with various beads and joints.
1-33
