Floor covering often displays some bizarre behavior which mystifies the end user and the flooring contractor. The changes which occur in the material, some rather soon after installation and others some time later are always the reaction to a condition or stimulus no one is aware of. Most of the time the comments will be similar to “I’ve never seen anything like this before” or “there must be something wrong with the material for it to do this” this being whatever it is the material is doing that no one can believe. Just because no one has ever seen what the flooring material is doing doesn’t mean what’s happening is abnormal. It may be different for them but chances are something like it or similar to it, has occurred before, in some way, shape or form. Let’s look at some examples and expose what they were hiding.
In one commercial installation a small area of about 200 yards of 28 ounce, straight row stitched, level loop nylon carpet was installed over a concrete floor using a spray adhesive. About a month after the installation the carpet started pulling away from the wall. It appeared the carpet was shrinking and in fact, it had. It was decided that to combat this problem a 12 inch solid colored border would be added to the perimeter of the room. By adding the border the separation of the original carpet from the wall would be eliminated and a design element added that complimented the installation. This seemed to be a great fix and everyone was satisfied. Three years later the carpet started pulling away from the border and now everyone began scratching their head and wondering what in the world could be happening now. The first question that must be answered is why is the carpet pulling away or shrinking from the border and does this have anything to do with the original problem of the carpet shrinking away from the wall. It would not be wrong to think there was something wrong with the carpet but it might not be the right thing to think.
What do we know here? We know the carpet was shrinking and that it did so within one month but why would it do it again after 3 years on the floor? Carpet that is not held in place will move – nylon carpet will expand and contract. Why was this carpet moving, early on and again now? If the carpet is not acclimated to the environment in which it is installed, prior to installing it, it will try to find its level of “relaxation” afterwards. This will result in it trying to move to that place. In the process of doing this it creates a lateral sheer force energy that literally pulls lineally, in width or length, across the plane of the carpet. If the carpet is not held firmly all over it will move in the path of least resistance. Since the perimeter edges of carpet in many glue down installations very often don’t get a complete full spread application, or in this case, the proper amount of adhesive sprayed on, it creates a weak bonding area. If a carpet is going to move the first place it will manifest the movement is along the perimeter – this is where the movement will be noticed.
Shrinking three years after installation is also the result of the carpet moving but now we have to look at some other factors. Why, if it was stable for three years did it now move and what stimulus was it subjected to or what was compromised to allow the carpet to move?
For carpet to move a couple of things have to be going on. The first is the product not having been acclimated to the installation environment prior to installation. What this means is the carpet was not allowed or given the opportunity to relax prior to being installed. If it does not relax it will try to do so once it warms up and it will find where it wants to go. Simply put, it will move when it relaxes and this will either cause it to expand or contract. If the adhesive has not anchored it securely it will move. Spray adhesive does not always have the greatest shear strength and a carpet that wants to move laterally across the plane can and will do so if it generates enough force. Fluctuation in the heating and air conditioning system can also cause carpet to expand and contract, again especially if it is not held securely in place or the adhesive looses its grip on the carpet. Cleaning the carpet with a system that puts a volume of water down and does not take enough up will also cause the carpet to shrink. When the carpet shrinks it can pull itself across the adhesive and the bond can be broken if the bond has been compromised in some way. Another factor is moisture in the concrete compromising the adhesive and allowing the carpet the freedom to move.
Since this carpet initially shrunk from the wall it would be reasonable to suspect it was not completely acclimated and that the adhesive was not aggressive enough to prevent it from moving. The border inset was a good idea and wise choice to correct this problem. Later, when the body of the carpet moved again away from the border it would be reasonable to suspect one of the other influencers. The one factor likely to be allowing this to happen is the adhesive and its lack of being able to prevent lateral movement of the carpet because it was losing its grip for whatever reason – which could be determined. The stimulus, which can only be determined by questioning what’s going on in the environment, could be any one of the things mentioned previously. If the carpet is not being held in place changes in the space environment could cause it to move. Wet cleaning, could, over a period of time, also be causing the carpet to move. A carpet not being held securely in place will be left to its own devices and move by expanding or contracting whenever it has the opportunity to do so. In this case the carpet was shrinking and this suggests moisture in some form coupled with the loss or compromise of adhesion.
Once this happens can it be fixed? Maybe. If the carpet can be pulled from the adhesive without a great deal of effort then it will lend itself to a potential fix. A “Crab” or Mini-Stretcher could possibly pull the carpets together so the space could be closed up. This would consist of freeing the carpet from the adhesive for a short distance from the seam, if possible and forcing it over with the Mini-Stretcher. It would have to be stay tacked in place and a fast setting, very aggressive adhesive, possibly even contact adhesive, used to re-glue it. The stay nails would have to be left in place until the adhesive dried and the carpet pulled over enough to give it some “fat” to spring back a bit. If this could not be done a new and wider border could be installed. However, three years time and use may not allow this to look as aesthetically pleasing as when the carpets were new. The other alternative is to replace the carpet and figure out what the cause of the problem was to prevent it from reoccurring.
At first glance this may seem like an installation related issue and it may be or partially be. Chances are it was the adhesive not being able to hold the carpet in place and then another stimulus came along and exacerbated and compromised the carpet and installlation. Spray adhesives can sometimes cause this type of problem and it wouldn’t be the first time it happened.
Carpet isn’t the only floor covering material that can shrink. Wood and vinyl will also shrink if not properly acclimated and held in place. Wood will likely shrink in the length leaving gaps at the end and vinyl will shrink along the perimeters and at the seams when it moves. Aside from properly acclimating the product, the guidelines which are provided by the manufacturer and the relevant flooring material association for the particular product, controlling ambient and substrate moisture conditions, are also necessary. For the sake of not sounding like we’re beating a dead horse, it cannot be stressed enough the importance of testing for moisture vapor emission prior to installation and controlling moisture in the air afterwards. Both conditions, out of control can and will affect the flooring material and the installation of it. Stone is the only thing that won’t move but its installation could be compromised depending on what was used to fasten it in place.
Vinyl would be more susceptible to movement with changes in heat and cold. The warmer it is the more it would move; colder and it would tend to shrink – only if not affixed firmly to the floor and if there were an inherent instability in the material. This could be relevant to sheet vinyl, planks, tiles or any other form of vinyl flooring material. Wood and wood component products are extremely susceptible to moisture. As we’ve said here before, wood in any form still must be thought of as a tree. It absorbs water, expands and contracts, dents, scratches, chips, and abrades. The part people seem to forget is that which deals with the influence of water on wood. Water will make wood change its form and if it changes this can result in gaps and voids in a wood floor.
Don’t forget to use common sense when you see floor covering moving on the floor. It means it is not being held in place and something is influencing it to cause it to move as a result. If you understand floor covering products and what they will and won’t do you can avoid trouble, whether you’re the end user, flooring contractor, architect, designer, specifier, cleaner or manufacturer. Remember, the flooring never lies, it will always tell you what’s wrong if you know how to interpret what its saying. That’s where our expertise comes in, we can always figure out what went wrong and why. It may not be what everyone wants to hear but it’s always the truth, painful as it may be.
Author – Lewis G. Migliore – The Commercial Flooring Report
LGM and Associates – The Floorcovering Experts