USG Levelrock Floor Underlayment Finished Floor - Manual (Page 7)

General recommendations
In all cases, follow floor-covering manufacturer’s installation recommendations to maintain
floor-covering manufacturer’s warranties .
Before applying any of the USG floor treatments and the floor-covering, all surfaces must be
clean and free of oil, paint, chemicals, wax, grease, dust, dirt and other construction debris .
The use of sweeping compounds on L
eveLrock
floor underlayment is not recommended, as
these products often contain oil, which can cause a poor bond between the L
eveLrock
floor
underlayment and the adhesive or mortar used to attach the floor goods .
Floor-covering Installation
L
eveLrock
floor underlayments accept virtually
every type of floor covering – from vinyl and
carpet to hardwood and marble tile . For a
successful finished floor, follow the specific
installation recommendations below .
carpet and Pad
A variety of carpets, carpet pads, and
adhesives can be used with L
eveLrock
floor
underlayment (see page 12) .
Glue-Down Attachment
Follow Surface Requirements instructions
to prepare the underlayment . Also, follow
floor goods manufacturer’s adhesive
recommendations . Prior to installation,
conduct a sample test to confirm bond
compatibility .
carpet Modules. Follow Surface
Requirements instructions to prepare the
underlayment . Install carpet modules with
100% adhesive coverage . A bond test
should be conducted no sooner than 72
hours after the adhesive has been applied
(cool temperatures and/or high humidity
may lengthen this time) . A successful bond
test should have 90-100% of the adhesive
remaining on the floor after the carpet tile
has been pulled up .
Mechanical Attachment
Note: Mechanical attachment of tackless
strips is not recommended when L
eveLrock
floor underlayment has been poured over
expanded or extruded polystyrene, over a
sound mat, or on the edges of a corrugated
deck installation . (See Adhesive Attachment
Tackless Strips .)
Tackless Strips over Wood Subfloors.
When L
eveLrock
floor underlayment has
been applied to a wood subfloor to ¾ in .
(19 mm) thick, use tackless strips such as
those manufactured by Halex Corporation
(halexcorp .com) . For thicker underlayment,
install filler nails every 12 in . to 18 in . (305
mm to 457 mm) o .c . Filler nail should be
long enough to penetrate at least ¼ in . (6
mm) into the subfloor .
Tackless Strips over concrete. When
L
eveLrock
floor underlayment has been
applied to a concrete subfloor:
· Install standard tackless strips with
concrete nails every 18 in . to 24 in . (457
mm to 609 mm) o .c . Concrete nails
should be long enough to penetrate at
least ¼ in . (6 mm) into the subfloor .
· Install diamond-point nails through the
tackless strip and underlayment with an
air compressor-driven automatic nailer .
carpet Tack Strips. If a carpet tack strip
is used, a 1-1/4 in . x 12 gauge spiral shank
anchoring nail is recommended for L
eveLrock
floor underlayments .
Adhesive Attachment
Tackless Strips. Follow the Surface
Requirements instructions . To attach tackless
strips to the underlayment, use PL 400 heavy
duty construction adhesive from OSI Sealants
or CX-948 polyurethane adhesive/sealant
from Chemrex . Before installing carpet, wait
24 hours after applying PL 400 adhesive;
wait overnight after applying CX-948
adhesive/sealant . (Apply CX-948 adhesive/
sealant with a minimum 3/8 in . bead, which
equates to 30 lineal ft ./10 oz . tube, where
the tackless strip will be placed . Do not
install more than 30 ft . of the product before
applying the tackless strip .)
Installation
7