Site Conditions
The environment in which the carpet is to be
installed must be controlled with the temperature
between 65° F and 95° F (18° C and 35° C) and the
relative humidity between 10% and 65%. The slab
temperature should not be less than 65° F (18° C).
These conditions must be maintained for at least 48
hours before, during, and 48 hours after the
installation.
Floor Preparation
The concrete must be inspected to determine the
special care that might be required to make it a
suitable foundation for carpet. All cracks, holes,
joints, and protrusions must be adequately addressed to
ensure a smooth, finished appearance and prevent
accelerated wear.
Concrete must be cured, clean, and dry, free of
paint, dirt, grease, oil, curing or parting agents, and
other contaminants, including sealers, that may
interfere with the bonding of the adhesive.
Whenever a powdery or porous surface is encountered,
a primer compatible with the adhesive to provide a
suitable surface for the glue-down installation should
be used. Patching compounds must be compatible with the
adhesive selected and latex- or polymer-fortified.
Manufacturer's recommendations for patch thickness
should not be exceeded. Large patched areas must be
primed.
Primers - The use of primers on floor
surfaces is generally not necessary except for sanded,
dusty, porous, or acoustical surfaces. Priming cannot
overcome moisture conditions and must not be used for
that purpose. When used, primers must be thin, fast
drying, and compatible with adhesives, which should be
applied only after primer is dry.
Where lightweight or acoustical concrete is used,
refer to the manufacturer's recommendations for the
proper primer to be used before carpet is installed.
Liquid Adhesive Removers - There are
liquid adhesive removers available that will effectively
remove cut-back or emulsion adhesive residue from
subfloors; however, there is evidence these products may
adversely affect the new adhesive or the new floor
covering. Any residual of these products left in or on
the concrete slab is capable of causing a failure. The
use of these removers may void all applicable
warranties.
Testing of Concrete Subfloors Prior to Adhesive
Installations
The owner or general contractor must submit to the
flooring contractor a written report on moisture and
surface alkalinity of the slab to determine its
suitability as a substrate for the material to be
installed.
Moisture Testing
Concrete floors, even with adequate curing time, can
present an unacceptable moisture condition by allowing
excessive amounts of moisture vapor to pass through to
the surface. This can be a problem even on suspended
concrete floors. All concrete floors should be tested
for moisture emission rate by utilizing an anhydrous
calcium chloride moisture test kit available from
installation supplies and accessories distributors.
This quantitative method is very precise and must be
conducted carefully, with strict attention to the test
kit manufacturer's detailed instructions. Moisture
emission rate is expressed in lbs/1000 sq ft/24 hours.
Because the calcium chloride test for emission rate
requires 3 days to conduct, proper installation planning
is a must.
As a general guideline, an emission rate of 3 lbs
(1.4 kg) or less is acceptable for most carpet. In the
range from 3 lbs to 5 lbs (1.4 to 2.3 kg), carpet with
porous backings can usually be installed successfully;
but the risk of moisture-related problems increases.
Since some floor covering products are less tolerant of
moisture than others, always consult the individual
manufacturer to determine the emission rate for specific
products.
Alkalinity Testing
A pH range of 5-9 is satisfactory. A reading above 9
requires corrective measures. Consult the adhesive
manufacturer for recommended testing and corrective
procedures.
Source of information: CRI-104,
Standard for Installation of Commercial Carpet.
|
