Figure 6-7.Fasteners for underpayment.
Figure 6-8.A1ignment of finish flooring materials.
angles to those in the subfloor. Be especially careful to
avoid aligning any joints in the underpayment with those
in the subfloor. Leave a 1/32-inch space at the joints
between hardboard panels. Particleboard panels should
be butted lightly.
FASTENERS. Underlayment panels should be
attached to the subfloor with approved fasteners.
Examples are shown in figure 6-7. For hardboard, space
the fasteners 3/8 inch from the edge.
Spacing for particleboard varies for different
thicknesses. Be sure to drive nailheads flush. When
fastening underpayment with staples, use a type that is
etched or galvanized and at least 7/8 inch long. Staples
should not be spaced over 4 inches apart along panel
Special adhesives can also be used to bond under-
payment to subfloors. They eliminate the possibility of
nail-popping under resilient floors.
Plywood is preferred by many for underpayment. It
is dimensionally stable, and spacing between joints is
not critical. Since a range of thicknesses is available,
alignment of the surfaces of various finish flooring
materials is easy. An example of aligning resilient
flooring with wood strip flooring is shown in figure 6-8.
To install plywood underpayment, follow the same
general procedures described for hardboard. Turn the
grain of the face-ply at right angles to the framing
supports. Stagger the end joints. Nails may be spaced
farther apart for plywood but should not exceed a field
spacing of 10 inches (8 inches for 1/4- and 3/8-inch
thicknesses) and an edge spacing of 6 inches OC. You
should use ring-grooved or cement-coated nails to
install plywood underpayment.
RESILIENT FLOOR TILE
After the underpayment is securely fastened, sweep
and vacuum the surface carefully. Check to see that
surfaces are smooth and joints level. Rough edges
should be removed with sandpaper or a block plane.
The smoothness of the surface is extremely
important, especially under the more pliable materials
(vinyl, rubber, linoleum). Over a period of time, these
materials will telegraph (show on the surface) even
the slightest irregularities or rough surfaces. Linoleum
is especially susceptible. For this reason, a base layer of
felt is often applied over the underpayment when
linoleum, either in tile or sheet form, is installed.
Because of the many resilient flooring materials on
the market, it is essential that each application be made
according to the recommendations and instructions
furnished by the manufacturer of the product.
Installing Resilient Tile
Start a floor tile layout by locating the center of the
end walls of the room. Disregard any breaks or
irregularities in the contour. Establish a main centerline
by snapping a chalk line between these two points.
When snapping long lines, remember to hold the line at
various intervals and snap only short sections.
Next, lay out another center line at right angles to
the main center line. This line should be established by
using a framing square or set up a right triangle (fig. 6-9)
Figure 6-9.Establishing center for laying floor tile.