Instructions / Assembly

TB92
CONCRETE CURING COMPOUNDS: WHAT TO DO WHEN
INSTALLING TILE OR A SELF-LEVELING UNDERLAYMENT
Technical Bulletin
Technical Services 800-282-8786
custombuildingproducts.com
install underlayment or ceramic tile over. Dissipating
curing agents rely on UV and abrasion by traffic to be
adequately removed. Many areas in a building will not
receive a sufficient amount of UV from sunlight to
Break down the coating and traffic patterns may be
insufficient to breakdown and remove the coating.
Further, the curing agent may have been applied at
different rates over the concrete, adding additional
variability.
Mock up vs. mechanical abrasion
For installations where a curing compound of any kind
has been used on the concrete, the owner can
decide to proceed at his own risk and accept liability
for the surface conditions. First, the floor covering
installer should build a mock up and perform tensile
tests onsite to evaluate bond results to support removal
of the curing compound before proceeding with an
underlayment or ceramic tile installation. If doing a
mock up on the existing surface, it is wise to select a
worst case scenario or test several areas.
Since the mock up assembly should cure a minimum of
7 days and ideally 28 days before performing the
tensile test, it may be more cost effective to shot blast
the concrete slab and remove all curing compounds
that way. Abrading away any curing compound on
the surface of the concrete will assure a good bond
with the use of a suitable cement underlayment or thin
set mortar.
If you suspect that the concrete surface that you are
about to bond an underlayment or tile to has been
treated with a curing compound, rely on the
experience of the many industry leaders and installers
involved with the ANSI and TCNA Handbook
committees and prepare the surface before the
installation of the flooring. It is not worth the risk that
the bond of the mortar or underlayment to the
concrete may fail and the floor covering will need to
be replaced.
Excessive moisture is another challenge that is
encountered when tiling over a new slab.
For information about moisture testing of concrete
slabs, or mitigating moisture vapor emission from young
concrete prior to the installation of tile or other floor
coverings, contact the CUSTOM Technical Services
Department at 800.282.8786.
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.
TB92/C 2/18R