The rubber backing frequently used under area rugs is a type of underlayment or pad utilized for cushioning, protection of the rug and floor, sound absorption and to keep the rug from moving when walked on. For many people, rubber is not always the first choice, due to potential yellowing it causes to vinyl flooring, chemical sensitivities and durability of the product. If you wish to avoid rubber, pick from several alternatives at a home improvement store or online.
Rug Pad Tape
Rug pad tape is a product sold in rolls and usually about 2 inches wide. There are two forms available. The first has adhesive on one side and is semi-tacky on the other, while the second option has adhesive on both sides, like double-sided tape. The tape is attached to the underside of the rug about 2 to 3 inches from its edges--all the way around the perimeter. This option is good in low-traffic areas and for smaller rugs that don't have a backing that can damage the floor where the rug makes contact. Tape, however, is not the best option for long-term use, since the adhesive tends to wear off after a couple of months.
Visco-elastic pads, commonly referred to as Memory Foam, are comfortable to stand on and come in a variety of thicknesses and sizes. While these types of rug pads generally don't have adhesive, they naturally keep rugs in place, as the memory foam is a high-friction material and will readily conform to the floor. In an age where there are already so many potentially harmful products, you probably don't want to add your rug pad to the list--especially if you are sensitive to chemical smells. Visco-elastic rug pads have one of the lowest amounts of "off gassing" (the release of volatile organic compounds or VOCs for short) and are Green Guard certified.
Another benefit is that these rug pads usually have a mold and mildew inhibitor built into them that acts as a moisture barrier. This means if something spills on the rug, you won't have to worry about it soaking through and ruining your floor. Since these rug pads are thicker, you will want to be cognizant of any doors that will need to open over the rug and ensure sufficient clearance.
Felt Rug Pad
The felt rug pad is a compressed needle-punched felt jute that is ideal for larger rug sizes (7-by-10 feet or larger). The felt pad doesn't have any direct nonslip properties but is weightier and thus stays in place. This style is great for sound absorption and comfort. The felt rug pad, one of the most natural of the rug pad options, can be used both on hard surfaces and carpet. The denser the felt, the longer it will last. When buying, therefore, look for the weight in ounces per square yard. Further, there is no moisture barrier with this option, so moderate spills can lead to floor damage if not quickly taken care of.
Organic Polymer Rug Pad
The waffle-style of rug pad texture is designed first and foremost to be nonslip on hard surfaces and is utilized by many rug pads of various materials. The organic polymer rug pad is one of the many types of waffle-patterned rug pads that populate the shelves in the rug aisles of home improvement stores. The difference between an organic polymer pad and other materials comes down to how the products perform and if you have chemical sensitivities to contend with. Organic polymer rug pads last longer than other common materials, including polyester fabric coated with PVC foam or the latex rubber, both of which are prone to breaking down over time. Organic polymer is made from plant-based materials and has very low VOCs, if any at all. This material doesn't provide much cushion, so if you plan to stand on the rug for an extended period of time (like in the kitchen doing dishes), the memory foam or felt rug pad is a better option.