Cutting edge advice about carpet joins

TO cut or not to cut: This question sometimes arises when installing woven carpets as well as carpets with extra backing material that I call selvedges. Some fitters don’t even consider this element of the installation. They think you should leave the selvedges on, because taking them off will reduce the strength of the construction.

Later in this article I will describe the strength of the edge. But first, I can recall when I started in the trade over 44 years ago. I recall sitting in my boss’s garage (work room) hand sewing body carpet together before we had to fit it onto felt underlay. The procedure was to allow the carpet to bed into the felt without leaving a ridge along the join, which we all know could be a potential wear spot.

Sewing normally pulled the two selvedges tight together and, providing there was not a wide selvedge, it would bring the fibres tight together without any gap. We did, however, have to remove some selvedges that were too wide, sealing the edges and then sewing together.

The amount of selvedge cut off was down to the skill of the installer. Back in the Sixties we did not have wide backing material on tufted carpets (at least the ones we used to fit). So this was not a
decision we had to make – whether we removed or left on the backing material. Modern manufacturing of tufted and woven carpets has changed with a wide selvedges, which need to be cut off particularly when heat seaming the joins.

In the early Sixties heat seaming had become a popular method of making joins in carpets, and providing you achieved tight edges, the join looked acceptable.

When making a join you should consider whether the selvedges are too wide for the method of joining.
On woven carpets, experience has shown that by placing the two edges together and viewing the gap, you can more easily decide to remove or leave the selvedge. As a guide, if the gap between the fibres is more than one row of tufts, remove one of the selvedges. Place the edges back together and if the gap is still more than one row of fibres remove the second selvedge.

Once you have cut into the weave, you must seal the edge to prevent fibre loss (fraying). This method will ensure there is no void for the fibres to fall into during usage. Removing selvedges can be done even with sewn joins, particularly when fitting on a firmer underlay to prevent a ridge along the join, which is a potential, wear area. When sewing, it is good practice to iron the join flat which will also reduce any ridge.

Removing selvedges is not difficult either by free hand following a shot (warp) or by using an Invisiseamer (produced by Inter floor) or a cushion backed or loop pile cutter (produced by Roberts).

Tufted carpets with wide selvedges should also be treated in the same way as for woven carpets, although the backing material can sometimes be inconsistent width. This may make an Invisiseamer more difficult to use than a trimmer or free hand.

The amount of gap should be the same – no more than one row of tufts missing between the join. Another consideration, when making joins in tufted carpets, is that when the manufacturer trims the carpet to size this is mainly done with a circular cutter that can shear the fibres part way along their length.

This will result in an obvious join because the edges look as if there are tufts missing. In fact, the tufts are shorter which give the same impression as missing tufts. With this in mind, remove a small amount of the edge to leave a consistent length of fibre along the join. This will result in a much better appearance to the join.

One golden rule is never say to the customer that a join will be invisible. Some textures, designs and colours disguise the join better than others, but if your customer is expecting an invisible join and is able to see it they are more likely to reject it.

Cutting a tufted carpet join is not difficult, particularly if using a trimmer as described above. If you receive a tufted carpet with a bow along the tufting line, I suggest cutting one edge straight, then using the Invisiseamer to trim the second edge to the first. Although tufted carpets do not fray as much as wovens, it is still a good idea to use a seaming adhesive to add strength to the join.

This is only an overview of making a good join, if you require more skills in this area The Academy of Flooring Skills offers short course at your premises covering this and many more subjects. C F J
John Roberts is founder of TAOFS (The Academy of Flooring Skills) and prominent consultant in flooring. TAOFS offers training in all types of floorcoverings.