How to Pick Carpet Pad

Determine the correct thickness for your carpet padding. According to the Carpet and Rug Institute (CRI), padding thickness is chosen based on the type of carpet being installed. CRI recommends padding no thicker than 7/16 inch for cut pile carpets, and no thicker than 3/8 inch for Berber or commercial carpets. Thicker padding can break down the backing of the carpet and dramatically shorten its useful life.

Check the quality of each pad. According to the Bane-Clene Corporation, you can check pad quality by squeezing each pad between your fingers. If the pad loses half of its height or more when compressed, it's not the best quality. Look for padding that is very firm and stays roughly the same height when compressed.

Review the density of each type of padding. The density of carpet padding is a measure of its durability, and is much more useful than thickness for comparing different types of pads. According to CRI, pads used in light-traffic residential applications should have a density of at least 5 pounds per cubic foot. For higher traffic levels, CRI recommends a density of at least 6.5 pounds per cubic foot, while all commercial applications require 12 to 14 pounds per cubic foot.

Compare the insulating properties of each material. According to Tim Carter at Ask the Builder, sponge rubber is the poorest insulator, and has an R-value of only around 0.21 per 1/2 inch. Padding made from jute fiber or urethane is a better insulator, with R-values of roughly 2.1 per half inch. If your floors tend to feel cold underfoot, look for the highest R-value you can find when choosing your carpet padding.

Compare warranties. According to the Utah State University Extension, quality padding should have a warranty that lasts for the life of the carpet. Some high-quality products may even have a warranty listed for twice the life of the carpet. Avoid padding that does not come with a warranty.

Consider allergies. Many people suffer from allergies, and carpet and padding are common triggers. According to the Utah State University Extension, felt padding is a poor choice for allergy sufferers. USU Extension recommends allergy sufferers choose padding made from foam, rubber or urethane.