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COMMERCIAL WORKSHOP
©
2002 APF SEMINARS
SPECIFYING
THE PROPER INSTALLATION TECHNIQUE
Sometimes in Commercial Carpet Installation we are faced with the task
of installing products that are doomed to fail regardless of the amount of
skill used during the installation process. These failures occur mainly
because an improper installation technique has been specified.
Architects
and Specifiers are usually the ones responsible for selecting the method
by which a particular project is installed. On occasions they either
mis-understand the product, installation method, local conditions or all
of the above.
There are
various reasons for selecting the method of installation on projects,
following are but a few; carpet construction, local conditions,
anticipated usage of the area, time constraints, budget, and aesthetics.
Following are
explanations of the major installation techniques currently used for
broadloom and modular carpets in the Commercial field:
TACKLESS/STRETCH IN:
This method employees the use of tackless strip around the perimeter
of the areas and a separate cushion. The cushion should be extremely dense
and limited in thickness to 3/8in. or less. The carpet is stretched in
over the cushion utilizing a Powerstretcher. In most cases, seams are
constructed using the Hot-Melt Tape Method; however, occasionally hand
sewing is specified. Carpet installed over cushion will have an effect on
reducing fatigue in people that stand or walk on the installed area,
however, this method of installation should only be used in smaller areas
where proper stretch can be attained. Also, consideration must be given to
the amount of foot and wheeled traffic as either, in excess, could cause
an installation failure due to wrinkling and possibly delamination.
Tackless installations could be very disruptive in an occupied area as the
nailing and possible drilling necessary to secure the tack strip produces
a fair amount of noise. The installation is also rather time consuming.
Future removal of this type of installation should be the most economical.
DIRECT
CEMENT/ GLUE DOWN:
Carpets installed via this method are glued directly to the substrate
using either the trowel method or a spray apparatus. Seams are secured by
the use of a seam sealer. This is probably the least expensive method of
installation available. Special attention must be paid to moisture and pH
when using this method of installation. The possibility of an increased
tuft bind is possible utilizing carpets constructed with unitary or
specialized backings. This will reduce the chances of seams running and
tufts pulling out. If cushion is desired, carpets with attached cushions
are available. Though most adhesives currently are designed to have low
odor and minimal VOC’s, in an occupied area, some people find the odors
objectionable. There are methods available that offer the feeling of a
cushion and the integrity of a Direct Cement Installation without the
adhesive odor. These methods are based on “peel and stick” installation
and are currently available through select manufacturers. Future removal
of direct cement installations can be rather labor intensive depending
upon the type of adhesive used and the backing of the product.
DOUBLE
GLUE/DOUBLE STICK:
High-density cushions are glued to the substrate using “pressure
sensitive adhesives”. The carpet is then glued to this padding using
premium adhesives. Seaming for Double Glue Installations can be specified
either utilizing the Hot Melt Tape Method or Chemical Seam Sealer Method.
Moisture and pH limits are critical to success and quantitative testing
should be performed prior to installation. The usage of special pressure
sensitive and premium adhesives drive up the initial cost if installation.
The Double Glue Method of installation is the most expensive from a labor
standpoint, as it requires a “double glue down”. Installers experience
“down time” waiting for the pressure sensitive adhesive to dry completely,
then there is additional time awaiting the premium adhesive to flash off
before the carpet can be installed to minimize it’s absorption into the
backing. As adhesives are used to secure the products to the floor, the
same problems that exist on the Direct Cement Installations in occupied
areas can occur. In addition to potential odor problems, Double Glue
Installations require that traffic be limited for a minimum of 24 hours
after installation. The quality of carpet selected for this type of
installation is also critical to the success of the project. The secondary
backing of the carpet, if tufted, must be a minimum of 10 Pic to allow for
structural stability and reduce the possibility of SBR “fallout” caused by
flexing of the backing during usage. Although release adhesives are used
during installation, future removal will most probably require the use of
a floor stripper machine and could run into considerable cost.
MODULAR
CARPET INSTALLATIONS:
Modular carpets are intended to be installed using “pressure
sensitive” adhesives either full spread or the grid and perimeter methods.
Manufacturers also have developed a “peel and stick” method that requires
the use of a primer prior to installation. Though the initial cost of
carpet tiles (modular carpets) appears to be higher, if extended over the
“life expectancy” of the installation, this method has proven to be more
cost effective in many ways. Reduced costs for repairs, and the
possibility of rotation of the carpets to extend the life by reducing
traffic patterns in effect lower the cost by extending the life
expectancy. Currently, carpet tiles are available with attached cushions.
If replacement is to be with carpet tiles, the cost will be lower as the
existing adhesive is re-usable, however, if replacing with Broadloom is
expected, the cost will be somewhat higher as the adhesive will need to be
isolated prior to replacement.
All
techniques are dependent on the local conditions at the time of
installation to ensure success. Temperature and humidity must be
controlled, traffic must be reduced and in some cases eliminated for a
specific amount of time. In the case of pattern installations, the job
schedule must follow a specific order to guarantee matching of the
patterns.
Utilizing the
best installation skills on a project that has a wrongfully specified
technique can and usually ends in installation failure. When faced with
this dilemma, installers should require, and receive prior to starting, a
job specific exemption from warranty on labor.
Other
installation techniques are available but the exotic nature of these
techniques limits their amount of usage and thus will not be discussed
here.
In order to
provide the best outcome on any project, the entire scope of that project
must be considered when specifying installation techniques.
WHEN
SHOULD TACKLESS INSTALLATION BE SPECIFIED?
In areas that require the use of a cushion, but are limited in size.
Individual offices and small areas lend themselves to this style of
installation. Areas that are considered “light commercial” with
limited traffic and no wheeled traffic may use this method. If
moisture or pH is a concern, but not excessive, the use of synthetic
cushion and carpets may be utilized. Their porosity allows for vapor
emissions to escape, and pH will have limited effect. When odors
from adhesives may cause disruptions. On projects where installation
noise can be tolerated. To mask MINOR substrate imperfections.
If immediate occupancy of the areas installed is a concern. This
method MUST be used with certain carpets depending upon construction.
Example: Carpets constructed on a Wilton Loom. The Tackless Method
may be used in the case of “temporary installations”, as damage to the
substrate will be minimal.
ALTERNATIVES TO TACKLESS INSTALLATION METHOD:
WHEN
SHOULD THE DIRECT CEMENT METHOD BE SPECIFIED?
Areas that are to receive heavy foot and wheeled traffic. If a high
tuft bind is required, utilizing this method of installation with a
unitary backed product is recommended. This method of installation
will enable a faster installation if time constraints are a consideration
on the project. From a budgetary standpoint, this is usually the
most cost-effective method of installation. Design capabilities are
increased at a lesser cost due to the increased speed of installation.
The possibility of pattern alignment is enhanced with this method.
ONLY if the substrate meets requirements for vapor emissions and pH levels
based upon the ASTM methods of testing.
ALTERNATIVES TO DIRECT CEMENT METHOD:
Manufacturers have developed an alternative to Direct Glue Installation.
This method is rarely used. Example: The Tac-Fast Method of
Installation. Modular Installation.
WHEN
SHOULD DOUBLE GLUE BE SPECIFIED?
Projects that require the use of a cushion but, need to eliminate the
possibility of wrinkling. Large areas where the Tackless Method of
Installation may fail. Areas that are to receive heavy traffic, both
foot and wheeled, and require the use of a cushion. On projects
where time and budget are of minimal concern.
ALTERNATIVES TO DOUBLE STICK INSTALLATIONS:
Attached cushion carpets installed via the direct cement method.
Tackless installations may be used if the areas to be covered meet the
criteria. Modular Installation.
WHEN
SHOULD MODULAR CARPETS BE USED?
Projects that expect excessive soiling and staining may find modular
carpet installations the better choice as they allow for easy “repair and
replacement”. If traffic patterns are expected to develop, tiles can
be rotated to allow for even wear. On projects that require
exceptional tuft bind qualities. Projects with partitions and other
de-mountable accessories will find modular installations more reasonable
from a cost standpoint. Modular installations allow expanded design
capabilities.
ALTERNATIVES TO MODULAR CARPET INSTALLATIONS:
Currently there are no viable alternatives to Modular Installation given
the benefits. However, Direct Cement of an attached cushion or a Double
Stick Installation may work for some applications.
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