Commercial Carpet: Pattern Matching and Seam Sealing
When it comes to the installation of commercial carpet, it seems like production is always the first thing on the agenda for many projects. It seems more often than not that the flooring installers are the ones who have to make up for the delays of a project, and they in turn get a shorter window of time to do their installations.
When a patterned carpet is being installed, the time it takes to match the patterns is often considerable versus non-patterned carpet. The need for educating the general contractor or end user to understand the time it takes to work with these types of products needs to be brought up prior to the installation of the carpet. If the type of carpet is already specified at the bidding stage, those bidding the work need to put the verbiage of the time it takes to install these types of carpets into their estimates and contracts. That way it’s been documented and can be addressed.
So now you’ve been awarded the contract. Congratulations! Should be smooth sailing from here, right? Not always. How many times have we seen an installation start where a few hundred yards of carpet have been installed and the patterns aren’t aligned, which then halts the installation until someone figures out what’s going on? This situation could be avoided prior to any carpet being installed if the installers knew what to look for. Although this article is about commercial installations, the same procedures apply to patterned residential installations as well.
The first thing to determine is if the carpet meets the manufacturer’s specifications for being in tolerance (Note: there are currently no industry standards for these tolerances, so they will vary by manufacturer).
What needs to be addressed? “Skew,” which is the squareness of the pattern (Photos 1 and 2). Tolerances range from 1” to 2” on average. Next is “bow,” which is the amount of deviation across the width, typically measured at the center of the breadth—though carpet can have deviation anywhere across the width (Photo 3).
“Pattern elongation” is where the pattern varies from one breadth to the next. A pattern will tend to grow from one side to the next, which is caused by uneven tension across the carpet during manufacturing (Photos 4 and 5).
Finally, we have “edge trueness/deviation,” where you might notice a wavy appearance of the patterns when looking along the length edge of the carpet. So here we are with our documentation of skew, bow, pattern elongation and edge trueness. We find that we are at the limits of what the manufacturer tolerances are, but we are still within those tolerances. So what now? Does it mean that if the carpet runs out of square it’s okay? If there is a bow in every breadth when looking across several breadths, is that okay also? And if the patterns run off and on along the length of the seam, do we simply say “it is what it is”?
Nope. What it means as an installer is you will need to manipulate the carpet to bring the skew, bow, pattern elongation and edge deviation back to square, with patterns matched and the carpet looking straight when looking down the length.
I can hear you now: “WOW! That takes way too much time Jon, and we don’t get paid enough to do all of that! And by the way, how are we supposed to manipulate the carpet to get it back to what manufacturers and the industry want?”
I’ve been to so many inspections after the carpet has been installed and asked the carpet installer, “Did you use a power stretcher to align seams or to address skew?” Many times the answer is: “We don’t use power stretchers on glue downs.”
If you’re installing a patterned carpet, there are a number of tools that are required in order for a proper installation. These include a power stretcher and a dead man—basically, a board with tackstrip on one side with the tackless pins all facing one direction (Photos 6 and 7). One is a fixed dead man while the other is referred to as a floating dead man, With the floating dead man, the carpet has the ability to move in between the two legs; the tackstrip is nailed to the two legs. Other tools include a “crab stretcher” (Photo 8), knee kicker, a string line or laser, framing square and straight edge, nails to “stay” the carpet and even tackstrip.
Regarding seam sealing, the traditional non-patterned method is to fold half the carpet back on two breadths, glue the area and then place the first half breadth into the adhesive. Once the first piece has been placed, the installer will seal along the edge with a seam sealer recommended for a glue down and proceed to leave a 1/8” bead (Photo 9).
Once this is done, the second piece is placed into the adhesive and then aligning the carpet along the seam begins. This method is fine because you don’t have to manipulate the carpet, but what if it’s a patterned carpet that is not matching at the seams? Applying seam sealer to one side before placing the next breadth in will cause the seam sealer to get contaminated with multi-purpose adhesive and worse than that, the seam sealer will have the potential of getting onto the face yarns of the carpet.
So does the installer just not seal the seam so he or she doesn’t create another headache and figure the multipurpose adhesive will seal the seam since the carpet will be manipulated? This approach won’t work either because the seam will not be completely sealed.
An alternative would be to “pre-seal” all the seams once they have been precut. This way, the edges of the carpet are sealed properly, the seam sealer will be dry and the carpet can be manipulated without getting seam sealer up on the face fibers. You will want to use a regular acrylic or universal acrylic seam sealer rather than the solvent-based (amber color) type of seam sealer when using the pre-seal method.
Looking at all the different steps required for a patterned carpet versus a non-patterned carpet, it’s easy to see why installers get frustrated when the pay is the same regardless of type. Having a patterned carpet at the upper end of what the manufacturer tolerances are takes hours or days to achieve what’s considered to be a proper installation. As an industry, we need to be the professionals and know what it takes to install certain products. We also have to make sure that retailers, general contractors and end users understand the time it takes to achieve the best installation.
Thanks for reading. Part two will cover the procedures to check carpet tolerances and installation of a patterned carpet. In the meantime, if you have the opportunity to attend an International Certified Floorcovering Installers Association certification (cfiinstallers.com) or Natural Fiber Installers Certification (nficnet.com) for patterned carpet, I highly recommend it.