Installation Guide
04.4.2018 | Page 4
Flexco Floors | 1401 E. 6th St. - Tuscumbia, AL 35674
P: 800.633.3151 | excooors.com | Made in the USA
TECHNICAL DATA SHEET
VINYL STAIR TREADS, RISERS & STRINGERS
Vinyl Treads
sheet at a rate of 400 sq. ft. per gallon.
When installing over concrete as moisture
mitigation, material must be applied in
two coats. Do not install flooring until
moisture testing has been conducted per
the appropriate standard and/or moisture
mitigation has been installed and is dry to
the touch. Do not install flooring in below
grade areas when hydrostatic pressure is
visible or suspected.
RESINOUS SUBSTRATES
When installing directly over a resinous
products, such as the Excelsior MM-
100 or an epoxy coating, ensure that
coating is dry to the touch and has
cured for the prescribed length of time.
Substrate must be clean, dry, sound and
free of contaminates. Ensure to follow
installation procedures and trowel sizes
for non-porous substrates.
GYPSUM BASED SUBSTRATES
Gypsum-based substrates must have a
minimum compressive strength of 3500
PSI. Gypsum substrates that do not meet
this requirement must have one coat
of the Excelsior MM-100 or equivalent
installed to improve the tensile/pull-off
strength of the substrate. Substrate must
be structurally sound and firmly bonded
to subfloor. Any cracked or fractured
areas must be removed and repaired
with a compatible patch or repair product.
Follow instructions for installation over
a gypsum substrate. New or existing
gypsum substrates may require a sealant
or primer. Follow all manufacturer’s
recommendations regarding preparation
for resilient flooring installation.
WOOD SUBSTRATES
Wood substrates must be constructed per
federal, state and/or local building codes.
Wood substrates should have a minimum
thickness of 1”. If plywood is being used,
ensure plywood is Underlayment Grade
with a minimum thickness of 1/4” and
is fully sanded prior to installation. When
stairs may be subjected to moisture, use
an APA approved exterior grade plywood.
Other wood materials, such as OSB,
lauan, particleboard, chipboard, fiberboard
or cementitious tile backer boards,
are not acceptable substrates. Avoid
preservative-treated and fire-retardant
plywood, as some may be manufactured
with resins or adhesives that may cause
discoloration or staining of materials. Do
not install stair treads, risers or stringers
directly over solid or engineered hardwood
flooring without first installing plywood
or a suitable cementitious repair product
at a minimum thickness of 1/4" over the
hardwood flooring.
Wood substrate deflection, movement,
or instability may cause stair tread
installations to release, buckle or become
distorted. As such, do not use plastic or
resin filler to patch cracks. Do not use
cement or rosin coated nails and staples
or solvent-based construction adhesives
to adhere the plywood. Do not install on
a sleeper system (wood subfloor system
over concrete) or directly over Sturd-I-
Floor panels.
METAL SUBSTRATES
Metal substrates must be thoroughly
sanded/ground and cleaned of any
residue, oil, rust and/or oxidation.
Substrate must be smooth, flat and
sound prior to installation. When installing
in areas that may be subject to topical
water or moisture and/or high humidity,
an anti-corrosive coating must be applied
to protect metal substrate. Contact a
local paint or coating supplier for coating
recommendations. Install stair treads
within 12 hours after sanding/grinding to
prevent re-oxidation. Any deflection in
the metal floor can cause a bond failure
between the adhesive and the metal
substrate. Be sure to follow installation
procedures and trowel sizes for non-
porous substrates.
EXISTING FLOORING SUBSTRATES
The suitability of existing flooring as
a substrate depends on the specific
requirements of the adhesive being
used to install the material. As such,
refer to the adhesive requirements for
existing flooring substrates and ensure all
adhesive requirements and guidelines are
followed.
3. CRACKS, JOINTS & VOIDS
All cracks, joints and voids, as well as
the areas surrounding them, must be
clean and free of dust, dirt, debris and
contaminants. All minor cracks and voids
3/64” wide or less may be repaired with
a suitable cementitious patch, such as the
Excelsior CP-300, or an epoxy filler, such
as the Excelsior EN-610.
Due to the dynamic nature of concrete,
manufacturer cannot warranty
installations to cover cracks or other voids
(such as control cuts, saw joints and
moving cracks or voids) wider than 3/64”.
Do not install flooring directly over any
crack wider than 3/64”.
To treat through cracks (depth at least
75% of the thickness of the concrete),
chase joint or crack with a suitable saw or
grinder and open to a minimum width of
¼”. Be sure to clean all dust, dirt and debris
from crack. Joints and cracks should then
be sealed with a suitable, elastomeric
caulk (such as Ardex Ardiseal Rapid Plus,
Mapei P1 SL or equivalent) designed for
use in expansion joints. Install a closed-
cell backer rod at prescribed depth and
follow caulk manufacturer’s instructions
for installation. Ensure surface is troweled
flush with surface of concrete.
To treat other cracks and voids (such as
control cuts, saw-cut joints and surface
cracks) over 3/64”, chase joint or void with
a suitable saw or grinder and clean all
dust, dirt and debris from crack. Fill entire
crack with a rigid crack filler (such as
Ardex Ardifix, CMP CM10 or equivalent)
designed for use in control or saw-cut
cuts. Follow material manufacturer’s
instructions for installation. Ensure
surface is troweled flush with surface of
concrete.
Review all manufacturer installation
instructions and/or consult
manufacturer technical staff for all
crack or joint filling products prior to
treating joints and cracks.
4. STRINGER INSTALLATION
Prior to the installation of stair treads and
risers, any specified Flexco Stringer or
equivalent must be installed (the inclusion
of Flexco Stringers is optional). Ensure
stringer material has been properly
acclimated and that ambient conditions
are within normal operational ranges.
Ensure all stringer materials have been
cleaned with a clean, damp cloth and
denatured alcohol or equivalent solvent-