Figure 5-19.Wall angle installation.
layout. In determining the number of 2-foot or 4-foot
cross tees for border panels, you must remember that no
more than 2 border tees can be cut from one cross tee.
The tools normally used to install a grid system
include a hammer, chalk or pencil, pliers, tape measure,
screwdriver, hacksaw, knife, and tin snips. With these,
you begin by installing the wall angles, then the
suspension wires, followed by the main tees, cross tees,
and acoustical panels.
The first step is to install the wall angles at the new
ceiling height. This can be as close as 2 inches below
the existing ceiling. Begin by marking a line around the
entire room to indicate wall angle height and to serve as
a level reference. Mark continuously to ensure that the
lines at intersecting walls meet. On gypsum board,
plaster, or paneled walls, install wall angles (fig. 5-19)
with nails, screws, or toggle bolts. On masonry walls,
use anchors or concrete nails spaced 24 inches apart.
Make sure the wall angle is level. Overlap or miter the
wall angle at corners (fig. 5-20). After the wall angles are
installed the next step is to attach the suspension wires.
Suspension wires are required every 4 feet along
main tees and on each side of all splices (see fig. 5-21).
Attach wires to the existing ceiling with nails or screw
Figure 5-20.Corner treatment.
eyelets. Before attaching the first wire, measure the
distance from the wall to the first main tee. Then, stretch
a guideline from an opposite wall angle to show the
correct position of the first nail tee. Position suspension
wires for the first tee along the guide. Wires should be
cut to proper length, at least 2 inches longer than the
distance between the old and new ceiling, Attach
additional wires at 4-foot intervals. Pull wires to remove
kinks and make 90° bends in the wires where they
intersect the guideline. Move the guideline, as required,
for each row. After the suspension wires are attached,
the next step is to install the main tees.
In an acoustical ceiling, the panels rest on metal
members called tees. The tees are suspended by wires.
Figure 5-21.Suspenslon wire installation.