No-Callback Carpet Installation, continued
Choosing a Carpet
Tufted carpeting, which accounts for 90% of all carpeting
produced, is made up of three layers. The tufting, or face
yarn, is stitched onto a primary backing, usually woven, of
slit-film polypropylene fabric. A secondary backing sheet of
woven scrim polypropylene mesh or non-woven polyester is bonded
to the primary backing with liquid synthetic acrylic (latex) or
occasionally other types of compound adhesives and extenders.
(Natural latex is used only on small, washable rugs.) The
secondary backing gives the carpet a firm "hand" and the
necessary dimensional stability for stretch-attachment to the
perimeter tack row.
The face yarn, or tufting, may be cut pile, loop pile, or a
combination of the two. Carpet fiber is made from any one, or a
blend of, six basic materials: the four synthetics —
nylon, olefin, polyester, and acrylic — and wool and
cotton. Ninety-nine percent of all carpet is made from
synthetic fiber, with nylon accounting for 67% of the pie.
Nylon is regarded as the most durable fiber and is available in
all carpet styles. Olefin has high stain- and fade-resistant
characteristics, as well as good moisture resistance. Most
often used in commercial carpeting, it's a good choice for
kitchens and bathrooms, sunrooms, and damp-prone basements.
Polyester has great stain and fade resistance but is a less
durable material than nylon and olefin. It's ideal for
children's rooms, where frequent spills and challenging stains
are likely. Acrylic is most commonly found in small area rugs,
such as bath mats.
Wool represents less than 1% of all carpeting but has a
luxurious feel and good durability. Generally, wool is
considerably more expensive than synthetic fibers. Cotton is
typically reserved for loose-laid area rugs.
Best choices. Carpet
quality is determined by fiber type and the density of the
weave; the more yarn stitches, or loops, per square inch, the
more durable the carpet and the better it will wear (Figure 5).
Heavy traffic areas, such as the family room, hallways, and
stairs, warrant the best, or densest, carpet the budget will
allow. Less dense carpet is a good choice for a bedroom or home
office, where traffic is relatively light. Manufacturers make
matching lines of carpet in various densities, so that a
lower-cost carpet in the bedroom will blend "seamlessly" with
the higher-performance carpet in the hallway.
Fiber density is the key to a durable carpet
— generally, the more yarn stitches, or loops, per inch,
the better the carpet will wear. Less dense material works best
in bedrooms, dens, and other low-traffic areas.Walk this way. Carpet can
and should be chosen to minimize the appearance of fiber
crushing. Carpet fibers in the traffic areas are not usually
worn away but become permanently deformed by repeated impact.
Short, dense, cut- or loop-pile carpet, often seen in
commercial spaces, is best for disguising high-traffic
walkways. Berber and sisal-style carpets, with their textured
surfaces and tight loops, are particularly effective at
concealing walkways and furniture marks, without presenting a
"commercial" look in a residential setting.
Performance guidelines.
Manufacturers employ a performance rating system to direct
carpet selection. The system varies from one maker to the next.
Usually, it's based on a five-point scale, with 4 or 5
designating carpet that's best for use in high-wear areas
(Figure 6). In a ten-point system, 8 to 10 will be the highest
performance rating.
Figure
6. Consumer information is listed on the back of most
carpet samples, offering application guidelines on a numerical
scale, usually from 1 to 5. Higher numbers connote heavier-duty
materials.
Installation
Stretched carpet is held in place by catching the carpet
backing on the sharp, opposing barbs of a perimeter tack row.
Normal 1-inch-wide tack row doesn't always hold carpet
securely, so some installers are switching to 2-inch-wide tack
row, which provides an additional row of barbs to securely snag
the backing (Figure 7).
Figure
7. To improve the tack row's grip on the carpet backing,
many installers prefer 2-inch-wide strips, which provide an
additional row of barbs.
Look for trouble. Before
installation, it's a good idea to look for color defects or
variation, missing or pulled pile loops, pole damage from
forklift handling, crush lines from improper storage, and any
other abnormalities. To avoid permanent creasing, carpet should
be stored in rolls; it should never be folded, other than brief
buckling to move it into the installation site.
Cold call. The vast
majority of callbacks on carpet installation jobs are due to
puckered or wrinkled carpeting. Although easily corrected, it's
also easily avoided with proper preparation and installation.
The room in which the carpet is installed should be maintained
at a temperature no lower than 65¼F to 70¼F, at
least 24 hours prior to installation. Relative humidity should
be between 10% and 65%. The carpeting should be unrolled, laid
out in the room, and allowed to acclimate for at least 24 hours
before it's stretched. Little time is lost to a proper
installation; the carpet can be rough-fitted while acclimating,
then seamed, stretched, and finished the following day. What
you're trying to avoid is stretching a cold carpet in a cold
room. When the heat's turned on, the warmed backing will expand
and relax, resulting in a loose, wrinkled carpet.
Admittedly, this is a tall order on a simple carpet
replacement job. Homeowners who have just crammed all their
furniture into the bathroom or out on the deck typically want
the installer in and out in a day. Acclimating materials isn't
on the schedule. However, some suppliers will accommodate this
snag by cutting and acclimating the carpet lengths for the job
in their heated warehouse, allowing the installer to pick up
the rolls just prior to installation.
Power-stretching the
carpet, rather than using the older technique of
"kicking-in," is essential to thoroughly extend and tension the
backing material. You should insist that your installer observe
this step. In time, most installers find that power-stretching
is also crucial to the long-term preservation of their knees,
which aren't designed for the impact that kicking-in entails
(Figure 8). Not surprisingly, many younger installers admit to
skipping the power-stretch step, relying only on the kick-in
tool and eternal youth to (inadequately) stretch the
carpet.
Figure
8. Although kick-in tools are essential to carpet
installation, industry guidelines state that final
power-stretching is mandatory to sufficiently stretch the
carpet. Installer's knee problems eventually bring them
painfully into compliance.
Because seam tape doesn't stretch with the carpet, seamed
edges should be stretched prior to taping. Seams should also be
treated with a liquid seam sealer before taping, to prevent
tufts from breaking out of the cut edge. This step is often
ignored, but loose and missing tufts loudly signal a seam's
presence. Some carpet types — some berbers, for example
— are more prone to seam "peaking" than others. Replacing
the standard three-inch-wide seam tape with six-inch tape helps
prevent peaking. Certain installers ignore this precaution,
simply because they don't own a six-inch seaming iron.
Glue-Down
More common in commercial installations than residential
applications, glued-down carpeting eliminates wrinkling
concerns, peaking seams, and the need for a perimeter tack row.
Gluing the carpet secures the entire field against displacement
under heavy use. The double-stick method, which involves first
bonding a carpet cushion to the substrate, then bonding the
carpet to the cushion, is the most durable installation.
Cushion-backed carpet enjoyed a brief run of popularity, but,
apparently, the backing tends to break down irregularly under
use, marring the surface appearance.
Removing a glued-down carpet isn't particularly difficult,
at least after you've gotten an edge started. Occasionally,
wood fibers from the top lamination of a plywood underlayment
will tear up with the carpet. To control this tendency, and to
make disposal easier, it's best to slice the carpet into
foot-wide strips before removal.
Resist asking your installer to stretch new carpeting
directly over an old glue-down job. Industry standards advise
against this practice, because the friction of the old carpet
pile will inhibit effective stretching. Plus, the old pile will
flex underfoot and unevenly stretch the new carpet, creating
"bubbles" in the surface.
Carpet and Radiant Floors
Carpet and cushion combined have considerable insulating
properties, with R-values up to 2, which may make carpet a
marginal choice over a radiant floor. Although inconclusive,
certain tests also suggest that when heated, carpet fibers
produce chemical emissions. If your clients insist on carpeting
their radiant floor, it's a good idea to make sure that the
home has a means of supplying a constant fresh air change to
avoid possible odor or air-quality complaints. According to a
recent article in Radiant Panel
Report, a thin, dense rubber pad is best over radiant
heat because it's relatively conductive and more resistant to
heat degradation. Wool carpeting is 1 1/2 times more insulating
than synthetic fiber; the best choice is any thin, synthetic
berber or commercial-type carpet. Ironically, radiant heat
provides one of the very things carpeting is chosen for, that
is, a warm feel underfoot. On a radiant floor, the best carpet
is no carpet.
Unavoidable Problems
One 25-year veteran installer jokingly comments that he used
to encourage party-goers to drop their cigarettes on the host's
carpet for "job security." A spilled glass of red wine can be
equally effective. Whatever the source, small burn holes and
permanent stains are simple to repair, especially when
installation remnants have been retained and stored by the
homeowner. The burned or stained area is cut out and a matching
carpet patch inlaid and secured with hot-melt seam tape. In a
pinch, the installer can "borrow" a patch from a closet or
other inconspicuous area and replace it with a compatible or
non-matching remnant.
Many carpets undergo a stain-resistance treatment at the
factory, and manufacturers offer warranties against staining by
certain common foodstuffs. Specific exclusions apply,
particularly to kitchen and bathroom installations, and to
certain stain sources like pets and abuse.
Heads up. Carpet suppliers
and showrooms often post noteworthy style-specific
characteristics and cautions on their sample boards, such as
"Difficult to seam" and "Can't be edge bound." It's a good idea
to inquire about any peculiarities common to the carpet being
selected.
Dave Holbrookis an associate editor at The Journal of
Light Construction. Thanks to Ross McDonald of McDonald
Installation Systems and Barbara Karras of Cloutier Supply
Company, who assisted with this article.