Sealing carpet seams

We’ve all seen it, those of us in the business who are always looking down, but also members of the regular public who can’t help but notice.

Christopher Capobianco

What I’m talking about are unraveling seams in carpet, or just visible seams that draw your eye.

When I started in the business in the early 1970s, I was big for my age, so my father, owner of a carpet store, would send me out on carpet installations as a helper. That was my weekend and summer job from about age 12 to 16. I watched a lot of carpet installers in that time, and the common wisdom was that if you did a glue-down loop pile carpet, you had to seal the seams. However, the practice of sealing seams in cut pile carpet or ANY carpet installed “stretch-in” over pad was unheard of. There were no other instances where seams had to be sealed other than “loop pile, glue-down.”

In the 1980s, I had started working as a volunteer in the area of installer training and had helped start an adult education program for resilient flooring and carpet installer training. I was invited to a summit meeting of sorts in Atlanta as the Floorcovering Installation Training (FIT) program was being developed. At that time, FIT was a non-profit entity that had input from across the whole spectrum of the industry including carpet, cushion, and adhesive manufacturers, installation contractors and people like me that were involved in installer training.

The Carpet and Rug Institute had published the early version of their Installation Standards, CR-104 and CR-105 and those were being used as a basis for the FIT carpet installer training program. I remember specific details of parts of the carpet installer training and certification were being discussed, and we got around to talking about seam sealer. Much to my surprise, I learned that they were going to recommend seam sealing of all carpets, not just the glue down loop pile pile I’d been taught need to be sealed. I remember questioning it and being educated about why it was so important. The CRI standards and the FIT program are still around today and this practice is still the industry standard that’s part of every carpet warrantee, even on a cut pile residential carpet.

Lee Senter, CFCRA president

Lee Senter, president of the Canadian Flooring, Cleaning and Restoration Association (CFCRA) and vice chair of standards for IICRC explained why the edge of every carpet should be sealed at the seams. “The biggest issue is that [during manufacturing] the adhesive that binds the primary and secondary backing is [mixed] with clay, marble dust and such things.” Those materials are likely to be affected by moisture, he explained, “So if the seams are not sealed on every cut edge, the exposed adhesive absorbs moisture and delaminates the carpet when the carpets are cleaned.” That’s when you notice on a slightly older carpet that the seams sometimes become more noticeable. This can also make people afraid to clean their carpets, and that’s not a good thing either. The lack of sealed seams, Senter explained, “is the hidden problem — the main issue will always be zippering seams” or worse, delamination of the backing at the seam edges.

So, that’s “by the book” but I find myself wondering about current practices.

I asked Leon Simon, president of Prosol Distributors in Montreal about this, and he said that, based on feedback he’s received, the practice I grew up with hasn’t changed, “We still use the liquid seam sealer for the glue-down and double-bond installation; we never use it for the stretch-in installation.” He said an exception is sewn seams, “Sometimes in wool carpet they use a bit of latex and they will sew the [seam].”

Not everyone agrees when it comes to stretch-in installation. Brian Garnier of New York is a master installer that worked with me on that installer-training program and was one of the first FIT-certified instructors. He was our carpet instructor and I did resilient. We both spent a lot of time instructing proper seam cutting and sealing. He advocated for carpet seam sealing on every type of carpet then, and still does. “It always gave me peace of mind to know I sealed my seams in case of any problems with the job,” Garnier said. “It does make a better seam when done correctly.”

The traditional method of sealing the edge of a carpet being installed over pad using a liquid seam sealer.

I remember working at a retail carpet store in 2004-05 that had a fairly high-end residential clientele. We had an installer that really wanted to go “by the book.” He went out of his way to deliver carpet a day ahead of time so it would acclimate, used a power stretcher instead of a knee kicker in many cases, and sealed all his seams. His attitude was that he was working with high-end products and getting paid well, so why take chances? Other installers questioned him on this, and I think some thought he was crazy. However, he had far fewer callbacks than other crews we had at the time and his work was flawless.

Keith Papulski is general manager of Denver, Colo.-based Taylor Tools, who manufacturers and supplies many types of floor covering installation tools and concrete substrate preparation and testing equipment. “Seam sealing is still required by carpet manufacturers for properly seaming carpets and will probably be required until carpet tufts are permanently bonded to the backing somehow,” he said. Years ago, there were no specialized tools available to make feeling the edges of the carpet easier on a stretch-in installation. I remember an early applicator bottle that came out about 15 years ago with a lip on the bottom of the applicator tip specifically for carpet over pad. That was a big deal then, as running a sealer down the edge of carpet before setting it into the seam tape became a bit easier to do. However, today there are many more options that are easy to use and provide a strong seam. Papulski explained, “ There are several different products available to do the seam sealing that range from bottles of liquid seam sealing adhesive, hot melt glue guns with special application nozzles to a one-step seam welding iron, all of which, when done properly, produce a non-fraying carpet seam.”

That last option intrigues me because it melts the seam tape onto the back of the carpet and also directs the hot melt to the edge of the seam. Technology sure has come a long way since I was a 13 year old!

As far as how widespread the seamsealing practice is, Papulski said, “I contacted several of our customers [who are] sundry distributors and they told me that they sell as many if not more seam-sealing products now as they did 5-10 years ago.”

So, as we have learned, although not everyone is doing it today, when installing carpet over pad and seaming with hot-melt tape, there is a big advantage to sealing the edges. The bottom line is that the carpet manufacturers’ warranties all require seam sealer on all carpets. So, if you are not doing it and you have a seam failure, you are on your own!

Christopher Capobianco has been in the floor covering industry since the 1970s in various roles including retail and commercial sales, technical support, consulting, journalism, education and volunteer work. He currently is part of the sales team for Spartan Surfaces in New York City. You can reach him via [email protected]


  1. Robert Trevino says

    I’ve been installing carpet for 20 years that seam sealer is messy! I actually have more complaints wen i do seal! from dust/dirt turning seams dark to hard carpet seam lines and even more difficult to put to gether with that sticky stuff everywhere..yea i know its timely process and needs done but send me a procedure that doesn’t take long,easy to apply and put together..

Speak Your Mind