A dealer called the other day and wondered if the rebond pad he had used, which had a oil/solvent odor, could be affecting the carpet installed over it, causing it to weaken and become loose. He said that he had experienced about six of these type problems over the last five years and wanted to know if we had heard of anyone else having this problem. At the time I told him that I had smelled pad that had an oil/solvent odor but had not heard of anyone having a problem with it relative to loose carpet.

The question made perfect sense. Solvent or oil will affect the carpet backing. To use an extreme example you can visualize, kerosene spilled on a carpet from a space heater will cause the carpet to bubble and buckle where the spill occurs. The kerosene is affecting the backing causing it to loosen and distend (stretch out). If an oily or solvent based material is emanating from beneath the carpet, whether it be in a pad or the substrate itself, it could certainly cause the carpet to weaken and therefore become loose because the backing would be affected. I told the dealer I’d look into his question further and get back to him.

After researching this issue and discussing it with one of our team associates we came up with an answer and some interesting information. The cross linking agent used in the rebond urethane pad adhesive may have been excessive. Because this substance is actually an oil an excess of it would create a sharp, pungent odor. If there was in fact an excess of this agent in the pad it could affect the backing of the carpet. In addition it may also try to cross link with the latex softening it, which would also cause the carpet to become loose. The softened latex could also cause other problems like delamination. There is no question oils and solvents, whatever their source, can affect the structural integrity or dimensional stability of a carpet. When this happens the carpet will respond by becoming loose or even coming apart where heavier traffic exists. Attempts to restretch the carpet will be futile because there is no way the carpet will be able to hold the stretch. The only recourse is to replace the carpet and the pad, if it is determined to be the cause of the problem.

Rarely does anyone think or implicate the pad as being the source of a problem. There have been all kinds of maladies that have affected carpet in the past due to weaknesses in pad. When poor quality, ½ thick, two pound density prime urethane pads were used extensively years ago it took no time at all for them to flatten out. This complete loss of resiliency in the pad, which always occurred in the traffic lanes, contributed to the carpet matting down and the carpet loosening up. If you tried to restretch the carpet over the failed pad, the carpet would actually be suspended over the void between the flat pad the backing of the carpet bridging it. As soon as the carpet was walked on again it would loosen up. The pad and not the carpet was the cause of the problem. This fiasco lead to the implementation of industry minimum standards for pad because of the problems it was causing. The industry standard adopted is 7/16 inch thick and 6 pound density according to CRI. The FHA standard is .525, which is about 9/16 inch thick and no less than 6 pound density. In reality, the lower the profile of the pad and the denser it is, the better performance you’ll get out of both the pad and the carpet. There are some great quality carpet cushions available that may cost you a little more but they’ll keep you from having some of the problems you complain about so often.

Other problems caused by carpet pad have been the yellowing, so prevalent just a few years ago most common with BHT in rebond pads. There are very few of these cases around today because the formulation of anti-oxidants in the pad has been changed. Another issue is the thickness of the pad. If the pad elevates the carpet above the pins on the tackstrip then the carpet cannot engage those pins in a proper perpendicular manner, this will result in the carpet coming loose. Again, the lower the profile or thickness of the pad, the better the engagement of the carpet onto the tackstrip pins. The denser the carpet pad, the less vertical and lateral movement there will be in the carpet minimizing or eliminating the chance for loose carpet. Naturally, the tackstrip will have to be placed the proper distance from the wall and the carpet power stretched properly.

Most people in the industry are unaware of pad issues and most actually don’t seem to care that much. No one pays enough attention to how many problems can be created by using the wrong pad and fewer yet give any consideration to the affect the wrong pad can have on the carpet. If you attend the LGM Carpet Seminar, you’ll learn a whole lot more about this product that can only help you with your business.