Installation Instructions

Introduction
Installing USG Fiberock panels
is quick and easy. Just follow
the simple installation steps in
this booklet to create a perfect
base for tile or floor coverings.
NOTE: Do not use USG
Fiberock panels over concrete
subfloors or over cushion-
backed vinyl.
Tools
Common tools like those
shown below are typically
all that are needed to install
USG Fiberock panels, though
additional, specialized tools
may be required with some
finish materials, such as tile
and natural stone.
Materials
USG Fiberock Panels
– Sizes and Packaging
– Joint Reinforcement
Behind ceramic tile, use
USG Durock
™
Brand tile
backer tape and latex-
based Type I mastic or
latex-modified thin-set
mortar. For sections that
will be painted, use paper
tape and setting-type joint
compound.
– Fasteners
Wall Application: For steel
stud applications (20 ga.
or equivalent), use 1-1/4"
or 1-5/8" USG Durock
™
screws for steel framing
(or equivalent). For wood
stud applications, use 1/4",
1-5/8" or 2-1/4" USG Durock
screws for wood framing
(or equivalent) or 1-1/2"
hot-dipped galvanized ring
shank roofing nails.
Floor Application: Use
1-1/4" USG Durock
™
tile
backer screws for wood
framing (or equivalent)
or 1-1/2" hot-dipped
galvanized ring shank
roofing nails. For resilient
flooring, use minimum 1/4"
crown chisel point staples,
hot-dipped galvanized ring
shank nails or corrosion-
resistant screws.
Fastener length should
be approximately equal
to combined thickness of
underlayment and subfloor.
Fasteners should not
penetrate through subfloor.
– Floor and Wall Framing
Floor Tile Applications:
Maximum joist spacing
24" o.c. The subfloor system
should be designed with a
minimum deflection limit
of L/360 for the span. Some
finish materials may require
a more rigid subassembly
(such as large format tile
and natural stone products
L/720). In these cases,
follow the manufacturer’s
minimum requirements.
The subfloor should be
APA Span-Rated Plywood
or OSB with an Exposure 1
classification or better with
3
Size
(thick x width x length) Units (pcs.)
1/4"
x 4' x 4' 60
1/4" x 3' x 5' 60
3/8"
x 4' x 4' 60
3/8"
x 4' x 8' 40
3/8"
x 3' x 5' 60
1/2" x 3' x 5' 50
1/2" x 4' x 8' 30
5/8"
x 3' x 5' 40
5/8" x 4' x 8' 24