FAQ
TB10
7/16" WONDERBOARD
®
LITE RATED FOR USE ON PLYWOOD
SUBFLOORS WITH 24" (61 CM) O.C. JOISTS
7/16" (11 mm) WonderBoard® Lite Backerboard has
been rated by the Tile Council of America (TCA) for
use as part of a ceramic tile installation system for
plywood subfloors with 24" (61 cm) o.c. joists. With
proper installation of the flooring system, the use of
WonderBoard® can achieve an “extra heavy” rating
for extra heavy and high impact use in food plants,
dairies, breweries and kitchens.
Custom® Building Products recommends this system as
an alternative to TCA installation methods F149 EGP
(double layer of plywood) and F147 (uncoupling
system) cited in the TCA Handbook. The double layer
of plywood method requires two layers of 23/32" (18.2
mm) Exterior Grade Plywood. The uncoupling system
consists of installing a 3/8" (9.5 mm) minimum layer of
plywood over the 23/32" (18.2 mm) plywood subfloor
and installation of an uncoupling system.
The installation system consists of one layer of 7/16" (11
mm) WonderBoard® Lite installed over the 23/32" (18.2
mm) plywood subfloor. WonderBoard® Lite is installed
per manufacturer's instructions using any CUSTOM®
ANSI A118.11 mortar as the leveling bed. This system
provides a more stable substrate on which to set tile
than the double layer of plywood method, and is less
expensive and labor-intensive than the uncoupling
system.
Any CUSTOM® polymer-modified ANSI A118.4 or
A118.11 mortar, such as VersaBond Flex® Fortified Thin-
Set Mortar, is recommended as the setting material for
this system.
Please contact CUSTOM® Technical Services or an
architectural representative for specifics on achieving
an “extra heavy” rating and further information.
The information in this bulletin is presented in good faith, but no
warranty, express or implied, is given nor is freedom from any
patent in as much as any assistance furnished by CUSTOM with
reference to the safe use and disposal of its products provided
without charge. Custom Building Products assumes no obligation
or liability therefore, except to the extent that any such assistance
shall be given in good faith.
Technical Bulletin
Technical Services 800-282-8786
custombuildingproducts.com