"It's easier to put on slippers than to carpet the whole world."
Carpet cushion (carpet padding) is the foundation for every residential carpet installation. Despite what you may be told, carpet padding plays an important part in the performance of your new carpet installation. However, the old adage that if you must choose between less expensive carpet and less expensive carpet padding, choose less expensive carpet is not true. Carpet selection and carpet cushion selection must enhance one another. Selecting either a poor quality carpet or poor quality carpet cushion ensures a carpet installation that is destined to disappoint.
Many retailers buy carpet cushion (carpet padding) in truckload quantities, so they typically use one type of carpet padding or another. They rarely offer several options, because of quantity discounts. Do not allow this to influence your carpet cushion selection decision. If a particular retailer does not offer a particular carpet padding that your prefer, ask if it can be ordered. If the retailer cannot or will not allow substitutions, find a retailer who will.
Absorbing the Abuse
Many consumers believe carpet cushion is used for the purpose of comfort under foot. While this a result of the use of carpet padding, the primary reason for carpet cushion is to absorb impact that the carpet would otherwise be subjected. This impact can cause synthetic latex to break down, backings to stretch, separation of the primary backing from the secondary backing (delamination) and unnecessary stress on the face fiber. The best performing carpet cushion actually provides less comfort under foot, but extends the life of the carpet installation by absorbing the abuse.
Two of the most common mistakes by consumers is to purchase a carpet padding that is too soft or too thick. Carpet cushion that is too soft, bottoms out when exposed to foot traffic. This allows the carpet to assume the rest of the impact burden; thus shortening carpet performance life.
What can get confusing is the various methods of rating carpet cushion performance. Some carpet padding is rated in density, but there are various methods for determining density. Terms like indentation load deflection (ILD), indentation force deflection (IFD), compression load deflection (CLD), compression force deflection (CFD) all may be used to describe the test method for evaluating carpet cushion density. Essentially these terms are a method of evaluating how much weight is required to bottom the carpet cushion out. Some of these methods use a square inch as the area for evaluation, while others use a broader are such as 6 or 8 square inches. It is important to note which method is used when comparing carpet padding, because an 8 lb. carpet padding using the broader area of evaluation may equate to a ½ pound rating for a square inch measure.
Also, carpet cushion may be rated in weight per cubic yard. An 8-pound carpet cushion may weigh 8 pounds in a standard 3 ft by 3 ft by 3-ft cube. A flat rubber carpet padding may weigh 22 pounds per cubic foot and a prime urethane carpet cushion may weigh only 4 pounds, but the ultimate performance factor is how many pounds per footfall area will it take for the carpet cushion to bottom out.