USG Fiberock Underlayment and Tile Backerboard - Manual (Page 11)

Countertop Application
Determine whether floor is level
by measuring distance
to desired tile height on both
sides of area to be tiled. If there
is a difference (i.e., the floor
is lower on one side), lay one
vertical row of tile from desired
tile height to low point of floor.
Affix tiles with tile-setting
materials. Use this first row as
a guide to keep tiles and grout
lines level and even throughout
installation.
If new flooring will be installed,
allow for thickness of new
flooring where the wall meets
the floor.
Installing Ceramic Tile
Always follow current ANSI
specifications and TCNA
guidelines for installing tile.
Apply tile-setting material to
tile backerboard with notched
trowel; key in mortar or adhesive
with smooth side of trowel to
prime F
iberock
surface first,
then comb out mortar or
adhesive in straight parallel
rows, hold trowel at min. 45º
angle to maintain uniform
thickness.
Working a small area at a time,
set tile with a slight twisting
motion and press into place. Keep
tiles aligned so joints are straight
and uniform. Use tile spacers if
desired. If excess adhesive
squeezes from under tile, remove
before it dries.
Cover plywood base with D
urock
tile membrane, 15 lb. felt or 4 mil
polyethylene and attach with 1/4"
galvanized staple.
Position
Fit ends and edges of panels closely,
but not forced together. Stagger
panel joints from plywood base
joints.
Fasten
Space fasteners 8" o.c. around the
perimeter and in the field of the
board.
Joining
Fill joints with latex-fortified mortar
or Type 1 organic adhesive and
immediately embed alkali-resistant,
fiberglass mesh joint tape.
Finish
Install tile.
Note:
Because cement board fasteners may
protrude through the plywood base when
1/4" cement board is used, 1/2" or 5/8"
cement board is preferred in this
application.
11