Foam Facts: The Importance of Carpet Padding

A carpet without great carpet padding (or carpet cushion) is like a peanut-butter-and-jelly sandwich without the peanut butter. Or jelly. But what makes it great? There’s a lot of science stuff involved. It all starts with Indentation Force Deflection (IFD). Try saying that three times fast.

What is IFD?

IFD might sound like something from a spaceship, but it’s an important part of your carpet padding.

IFD is a way to measure the firmness of a foam cushion—how it feels and how it yields to weight and pressure. This term is used not only with carpet, but also with furniture and mattresses that have foam cushions in them.

How it’s measured

Can’t you tell how firm or soft a surface is by simply plopping down on it? Actually, not exactly. Turns out, there’s a more scientific approach.

A sample of the foam is placed in a machine that pushes a disk-shaped compression plate (usually made of aluminum or steel) onto the foam. The machine applies varying amounts of pressure to determine the firmness, stiffness, and load-bearing capacity of the foam.

Why does it matter?

Firmness affects performance, comfort, and durability. If you have higher-quality carpet padding, it makes your carpet more comfortable and keeps it looking newer longer. If it’s subpar, your carpet can wrinkle, buckle, and appear worn more quickly.

Choosing your carpet padding

Consider the type of wear and tear the carpet cushion will be exposed to. Bedrooms, lounge areas, stairs, and other lightly trafficked rooms can use thicker, softer padding. Thin, firm padding is ideal for heavily trafficked areas.

In general, look for carpet padding that’s between 3/8 and 7/16 inch thick, with a density of 6 pounds per cubic foot. Make sure that the padding has been Green Label Certified by Carpet and Rug Institute.

Beyond IFD

Carpet padding is like a sponge, soaking up liquid from rainy-day foot traffic or accidental spills if there’s nothing between the padding and the carpet backing. The solution? Look for padding with a breathable moisture barrier designed to protect your subfloor and make cleaning easier.

Need softness underfoot? See how carpet padding makes a difference.

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