Product Brochure

wedi Building Panel (incl. Preline)
General Requirements
 wedi Product Systems are only used for interior installations.

Do not use as a wear surface or without tile / stone or other suitable coverings.
 Do not use organic mastic adhesives for setting tile on wedi Systems
in wet areas.
 Use only thinset mortar setting materials suitable for installation and
adhesion to the specific substrate / subfloor type.
 In steam showers or steam rooms use only setting materials specifi-
cally recommended by the manufacturer for this application, and sub-
merged and hot temperature areas. Setting materials recommended
by wedi are commonly solid epoxies (meet or exceed ANSI 118.3) or
high performance modified mortars (meet or exceed ANSI 118.15).
Test the adhesion over vapor barriers.
 Adhesive coverage under tile or other suitable surface finishes in wet
area installations must be a minimum of 95%.
 Certain substrates must be primed prior to thinset mortar attachment.
 Ensure tile and setting materials, including grout, are suitable for the
application (e.g. submerged applications or steam rooms)
 Do not use where substrate is subject to excessive moisture and mois-
ture content changes.
 Do not use over substrates including, but not limited to: general par-
ticle board (specific exceptions apply), luan, asbestos, plank, bamboo,
hardwood, chipboard, sponge backed vinyl tile/flooring, laminates, fi-
berglass based surfaces, metal or steel surfaces. Do not install over any
dimensionally unstable surfaces. Consult wedi for questions regarding
specific approved installations not listed here.
 Subfloors must be clean, even, sufficiently load-bearing and dry
(cured). Residues, oil, waxes, grease or other contaminants acting as
possible bond breakers must be removed.
 Deflection of all subfloor installations must not exceed L/360 for ce-
ramic tile installations and L/720 for dimensional stone installations
over wedi product under consideration of live and dead loads mea-
sured between joists.
 Any leveling of the subfloor must be done prior to installing wedi prod-
uct and tile. Subfloor maximum variation from plane must not exceed
¼” (6.4 mm) in 10 ft. (3050 mm) and 1/16” (1.6 mm) in 12” (304.8
mm) when tile over wedi product is used and all edges of the tile shorter
than 15” (381 mm). For installations over wedi product using tile with at
least one edge 15” (381 mm) or longer in length, maximum allowable
variation is 1/8” (3.2 mm) in 10 ft. (3050 mm) and no more than 1/16”
(1.6 mm) in 12” (304.8 mm). Make sure to use leveling materials ade-
quate to the challenges of the application. When leveling or building up
larger areas including outside the shower please do not use material that
can be affected by even low water exposure.
 wedi products should not be installed over bowl shaped, uneven
structures unless suitability is specifically determined for a wedi product.
 A wedi installation does not replace the need for Expansion and/
or Movement joint placement within a tile installation. Please follow
recommendations found in the TCNA guidelines (Detail EJ171).
 All installations shall be in conformance with IRC for residential installa-
tions and IBC for commercial installations or applicable building codes
in a region including the consideration of properly designed substrates
and subfloors. All installations including the consideration of properly
designed substrates and subfloors should be in compliance with cur-
rent TCNA Handbook for Ceramic, Glass and Stone Tile Installation,
use details specific to “Cementitious Coated Extruded Foam Backer
Board”. wedi’s technical recommendations supersede all requirements
of IRC,IBC, IPC or TCNA where in conflict and exceeding minimum
requirements established by the above mentioned institutions.
 Contact wedi for installation of tile or stone smaller than 2 × 2”
(50.8 × 50.8 mm) and larger than 12 × 12” (304.8 × 304.8 mm) over
wedi product, and where wedi Building Panel is used in commercial
use areas, to learn more about the best practices and requirements
applied in such applications. Follow tile manufacturers‘ recommen-
dations for appropriate flooring tile choice, setting materials and in-
stallation techniques.
Installation over structural
wooden surfaces – Flooring
 Plywood subfloor joist spacing must not exceed 16” (406.4 mm) o.c.
with minimum thickness of T&G exterior grade plywood of 23/32”
(19 mm). Joist spacing in excess of 16” (406.4 mm) o.c. and up to 24:
a structure comprised of one 23/32“ (19 mm) exterior grade plywood
with 1/8“ (3.2 mm) of a gap between sheets and one additional layer
of minimum 3/8“ (10 mm) thick exterior plywood with 1/8“ (3.2 mm)
gap between sheets.
 Plywood subfloor sheets must be properly glued and fastened.
 Wood subfloors and structures attached to wooden subfloors must
be kept dry and wood moisture content must be maintained at
consistent service and use levels and must not exceed 15 %. Where
constant moisture or vapor is present, ventilation must be installed
to eliminate exposure of the wood structure from below the wedi
product layer.
Installation over structural concrete /
cement base surfaces – Flooring
 Concrete slabs or other structural cement based substrates must be
fully cured (at least 28 days but up to 3 months for new Portland
cement based concrete or lightweight concrete under normal condi-
tions, mix ratio and ambient climate). Field verification of full cure (see
moisture level indicators below) is necessary to determine a full cure.
 Residual humidity must not exceed the following value per each floor
type when setting wedi product and / or tile coverings:
 Calcium Sulphate Screeds: 0.5 %
 Calcium Sulphate Screeds, heated: 0.3 %
 Cement Screeds: 3.5 %
 Gypsum based underlayment: 1 % or per manufacturer recom-
mendation
 Anhydrite Screeds: 0.5 %
Conduct measures with CM device.
Please note that wedi product systems might trap rising moisture
during cure time or in general from unisolated concrete ground floors
not equipped with a vapor barrier.
 Concrete Subfloors must not be subject to hydrostatic water pressure.
 Existing cracks in subfloor must be filled and secured.
 Do not use over control and / or expansion joints subject to out-of-
plane movement or in- plane- movement.
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