Product Brochure

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appropriate wedi Building Panels directly over framing
studs. Deflection of all subfloor and wall framing
installations must not exceed L/360 for ceramic tile
installations over wedi product and L/720 for dimensional
stone installations over wedi product under consideration
of live and dead loads. Measurements are taken on the
wooden subfloor in the center between floor joists. On
concrete floors, measurements are taken in the center
between beams or calculated based on formulation and
design. On walls, measurements are taken mid-framing
stud and mid-track or plate on framed walls. You can
find design requirements and recommendations in the
following: the International Residential Code (IRC),
International Building Code (IBC), the Engineered Wood
Association (APA) manuals, The Steel Framing Alliance
guides, American National Standards Institute (ANSI),
American Society for Testing and Materials (ASTM), and
Test Methods and the Tile Council of North America’s
Handbook for Ceramic, Glass and Stone Tile Installation
(see Details for “Cementitious Coated Extruded Foam
Backer Board”).
Minimum design requirements for substrates:
 Wood subfloor joist spacing up to 16 in. o.c. use with a
minimum thickness of 23/32 in. T&G exterior grade or
Exposure 1 rated plywood or OSB of 23/32 in. with 1/8 in.
of a gap between sheets.
 Wood subfloor joist spacing greater than 16 in. o.c. and
up to 24 in. use with a structure comprised of one 23/32
in. T&G exterior grade or Exposure 1 rated plywood with
1/8 in. of a gap between sheets and one additional layer
of minimum 3/8 in. thick exterior rated or Exposure 1
rated plywood with 1/8 in. gap between sheets.
 Wall framing is made of 2 x 4 wood framing studs or metal
studs 20 ga. or heavier. Wall framing studs are generally
spaced no greater than 16 inches o.c. and fully support
all wedi Building Panels in all corners of the framework.
Framing spaced greater than 16 in. o.c. and up to 19.2
in. o.c. can be covered with wedi Building Panel in 1 in.
thickness. Framing spaced greater than 19.2 in. o.c. and
up to 24 in. o.c. can be covered with wedi Building Panel
in 2 in. thickness. Contact us for specific solutions that
work with framing studs spaced or designed differently
than listed here.
 Shower seats and benches must be designed and
constructed to meet the same deflection criteria as used
for subfloors. In addition, they must provide a solid
substrate over framed studs for the horizontal seat area,
such as plywood sheeting.
 Semi-freestanding wall framing or half/pony walls must
be designed and constructed to meet the same deflection
criteria for regular integrated wall framing. In addition,
they must be reinforced to avoid the excess potential for
movement, especially as their outer framing posts are not
fully attached to other construction.
 All wedi Building Panels can be used over suitable
subfloors.
 wedi Building Panels from 1/2 inch thick or more may be
used directly over framing studs on walls or underside of
ceilings.
 All wedi Fundo shower bases and curbs must be installed
over a subfloor and cannot be installed directly over floor
joists.
 Do not use wedi products over substrates including, but
not limited to: general particleboard (specific exceptions
apply), luan, asbestos, plank, bamboo, hardwood,
chipboard, sponge-backed vinyl tile/flooring, laminates,
fiberglass-based surfaces, metal or steel surfaces. In
addition, do not install over any dimensionally unstable
surfaces. Consult wedi for questions regarding specific
approved installations not listed here.
 Existing cracks in subfloor must be filled and secured.
 Do not use wedi product over control and expansion
joints subject to out-of-plane movement or in-plane
movement.
 Suitable floor substrates must be level within the
permissible range. Any leveling of the subfloor must be
done prior to installing wedi products and tile. Subfloor
maximum variation from plane must not exceed 1/4 in. in
10 ft. and 1/16 in. in 12 in. when tile over wedi product
is used and all edges of the tile shorter than 15 in. For
installations over wedi product using tile with at least
one edge 15 in. or longer in length, maximum allowable
variation is 1/8 in. in 10 ft. and no more than 1/16 in.
in 12 in. Make sure to use leveling materials adequate
to the challenges of the application. When leveling or
building up larger areas, including outside the shower,
do not use a material that can be affected by even low
water exposure.
 Suitable substrates, where planes change, must be
squared to allow for a safe fit and connection between
wedi products joined in an assembly.
 Suitable substrates must be dry and cured within
permissible range before installing wedi products and
must be kept dry after installation.