A Carpet Installer's Notebook

Photo 1
Berber seaming can be a problem. As we discussed a couple of issues ago, the distance a seam will peak, or the tape will rise to get in line with the stretch, is equal to the thickness of the carpet back. That's why Berbers peak so badly. Six-inch seaming tape and irons were invented to deal with that problem. They helped by spreading the rise of the tape over a larger area, reducing the visual impact, but not eliminating the peaking.

Photo 2
Let me share with you a technique I developed to deal with Berber seam peaking in the early '80s. By the time six-inch had been invented, I had eliminated my Berber seam peaking problems as well as that nasty fuzz line you will get on Berber cross seams. It all started one day installing a piece of level loop carpet. Cue dreamy music and swirly visuals as we go back in time. I had made a great seam, row cut (although I must admit I didn't seal the seam); it was beautiful. Then after I stretched, the tape rose up, the seam peaked, and the rows separated a wee bit and there it was: the dreaded seam grin.

Photo 3
I solved the problem by running a small bead of glue from my hot glue gun down the seam, gluing the base of the rows together closing the gap. While doing this, the thought occurred to me "Why not do this while making the seam and eliminate a step?" What was born was the following seaming technique. I have been using this technique since 1980 and teaching it around the country since 1990 when I started working for Roberts as one of their tech managers. It's pretty simple and easy to master, just requiring a little practice to adjust your timing.

Photo 4
What you will need: your seaming iron of course, a hot glue gun with an extension tip, an extension cord, and a multi-plug adapter (Photo 1).

Photo 5
What you will achieve: elimination of the fuzz line on cross seams, elimination of row separation (smiling) on length seams, and greatly reduced seam peaking.

Photo 5a
It's important for the extension tip to have a mall aperture opening to allow better glue control. Photo 2 shows, on the left, a purchased small aperture tip (available from Crain or Taylor) far right, the tip that came with my gun. In the middle is that tip with the hole made smaller by putting a carpet sewing needle, or a large safety pin, in the opening for a spacer and pinching it closed with a pair of pliers.

Photo 5b
First, cut your seam as usual, open a row and row cut (Photos 3 & 4). After thoroughly melting the seam tape adhesive, move your iron forward, no more than an iron's length; I usually move mine 1/2 to 3/4 of an iron's length (Photo 5). Before pressing the two sections of carpet into the melted adhesive, apply a bead of hot glue on one side of the seam, at the base of the yarn where it meets the carpet backing (Photo 5a).

Photo 5c
Let me digress here for just a moment for those of you concerned about sealing edges with hot glue instead of latex. The worry, I am told, is "What if an inspector shines his blacklight and the hot glue doesn't fluoresce?" The following two pictures, (Photos 5b & c), one under a blacklight, one under regular light, show three glue sticks, one from Orcon, one from Gundlach, and one bought at an Ace Hardware store. They are lying on a piece of seaming tape. As you can see, they all fluoresce.

Photo 5d
Using a glue gun with a small aperture extension nozzle not only allows you to control the amount of glue, but also where and when it is applied. Put the seam together and force the bottom of the loops together pressing sideways with your thumbs from about 1/4-inch away from the seam edge (Photo 5d). Press up and down that length of seam a couple of times before using your seam roller.

Photo 6
On some soft Berbers, you may feel a hard line in the seam. This is really only noticeable if you are standing directly on the seam barefoot. If you put way too much glue on, you will get a big ugly lump, and when you remake the seam, you’ll be more careful. That was another lesson from the school of hard knocks for me. Cross seams require a slight variation on the theme when it comes to the cut. In the following photos, I am cutting a cross seam from the back on an angle, not because you should cut a cross seam on an angle. Follow a row whenever possible for length or width.

Photo 7
This is the problem with Berber cross seams: (Photo 6) these uncut loops, when cut, create the fuzz line at the seam. In some cases you might as well have a neon sign saying, "The seam is right here!" What we want to do is eliminate that fuzz. Cut any uncut loops off at tight to the base of the backing (Photo 7). Do this on both edges. The end result is two clean edges with virtually no fuzz (Photo 7a), but a small problem of a gap where you had cut away the uncut loops (Photo 8). Don't panic; this is solved by the same technique you used on the length seam.

Photo 7a
Yeah, I know it goes against everything you have ever thought or been taught about seams: "Don't cut fabric away from the seam edge!" I must admit, I cringed every time I did it for the first six months or so that I made Berber cross seams this way. But, the results were so outstanding I couldn't stop (Photo 9).

Photo 8
These next two photos show how the seams resist opening under pressure one length (Photo 10) and the cross seam (Photo 10a). One night, an installer at one of my clinics said, "Why do that? Customers are never going to bend the seam like that." I looked at him with astonishment and replied, "Of course not, this is to show if it resists this pressure, just imagine how it holds down seampeaking." By using this technique I had, by the time six-inch tape was invented, eliminated my Berber seaming problems, both peaking and the cross seam fuzz line.

Photo 9
Now I would like to add a couple of final thoughts on seampeaking. This column completes a series of three columns on seampeaking, with a small break last issue. In this series I have shared what works for me; if you have something better, please share it. If you are having no problems at all, stick with what you are doing. Let me insert a word of caution here regarding these tips. While it is not necessary on most carpets, you should use a heat shield on very soft or fine denier yarn cut piles If you don't have one, make one out of cardboard (Photo 11). The heat shield will slow down the reactivation of the hot glue on the edges, preventing fine yarns from getting trapped. This is what stopped me from using this Berber seaming technique on cut piles. It was too hard for me to control the glue gun. Now don’t let this stop you from using these sealing tips. It doesn't make them bad to use; you just need to exert the correct control.

Photo 10
As my final thoughts on seam peaking, I would like to respond to a letter to the editor from James Mullins, Tech services with Shaw Industries, whom I have a great deal of respect for. In his letter regarding my column "Seam Peaking Causes and Solutions Revisited," Mr. Mullins took issue with the stretching pattern I suggested, stating it was incorrect, that the majority of the stretch should be taken in the width. Citing the observation that in most of the carpets needing to re-stretched, the wrinkles they see run lengthwise, to repair that problem, the carpet needs to be stretched widthwise. He used an analogy of stretching a rubber band to support his theory. He stated that if you stretch a section of a rubber band lengthwise, the sides pull in, and when you stretch the width, you are only returning it to its original width, therefore not stretching the width at all.

Photo 10a
First let's make perfectly clear what that column was about: reducing seam peaking. If you do the majority of your stretch in the width, you have guaranteed seam peaking. Second, in all likely hood, the re-stretch problems he is seeing are probably from an improper stretch to begin with, carpet kicked in and not power stretched. As for the rubber band analogy, have a friend help you with this: have your friend pull the length of the rubber band and sure enough the sides will come in. Now, without him releasing the stretch on the length, you grasp the sides and return the rubber band to its original width. What do you think? Is the width stretched tight? You bet it is.

Carpet is made in rows running the length with an empty space between the rows. If a carpet is going to wrinkle, where do you think it will wrinkle? The path of least resistance, I would think, between the rows. Like a piece of seam tape, which way does it bend easier, with the rows or across them? As for the stretching, I am a firm believer in power stretching. My rule of thumb of how large a room should be to use a power stretcher is that if it is bigger than a phone booth, power stretch it. I never said don't stretch the width. I said do the majority of your stretch in the length on angles. The length is where carpet stretches the most; the width is where you will get the least stretch. The techniques I outlined in that article are techniques that work for me. I don't have re-stretch problems.

Photo 11
Mr. Mullins closes with the standard mill line "stretch the carpet 1 percent to 1 1/2 percent on both the length and the width." I am so tired of hearing that pat answer from the mills. Do you know how much 1 percent to 1 1/2 percent is? Twleve-foot carpet is 144 inches wide; 1 percent is 1.44 inches; 1 1/2 percent is 2.16 inches. How many 12-foot pieces of goods do you work with that will stretch even 1 inch in the width? Not many. Berbers? Forget about it.

For the mills to suggest all carpets should be stretched 1.44 to 2.16 inches in the width is ludicrous. Power stretch as I suggest in that column, use these new sealing tips for hot glue guns and your seam peaking problems will be significantly reduced and without the worry of future re-stretches.