Carpet padding
Credit: Bob Kast / illustration

Dear James: The carpeting in our living room needs to be replaced. I know how to evaluate and select the carpeting, but what is the best padding type and thickness?

— Sheryl T.

Dear Sheryl: Installing the proper type of carpet padding (called cushions professionally) is as important to the comfort and life of the carpet as the carpet itself.

Intuitively it seems like thicker padding is better, but that is not always the case.

It is not surprising that the padding selection is confusing because many of the carpeting ads highlight the thickness of the padding as an indication of value.

In addition to the thickness, the padding material itself is important, perhaps even more so.

First, you must understand the purpose of carpet padding and how it works to determine which type is best for your home and family. A properly carpeted house will have different thicknesses and densities of padding in various rooms and areas within rooms.

Carpet padding is designed to absorb the impact of feet on the carpet, control the flex of the carpet backing, provide comfortable walking and to provide some insulation over cold floors.

If a carpet pad is too thick and not very dense, it flexes a great deal as you walk on it. This may feel nice at first, but you will quickly begin to notice that your vacuum cleaner bag is getting full of carpet fibers.

This excessive flexing of the carpet backing actually breaks it down and the carpet fibers fall out.

On the other hand, if there were no padding, the fibers themselves would take the full impact of foot travel and they would break off and wear down quickly.

In most areas of the home with moderate to heavy foot traffic, a relatively thin (⅜ inch maximum) high density carpet pad is best. This provides adequate cushioning for comfort and fiber life, but it does not allow the carpet backing to overflex and disintegrate prematurely.

In other areas of your home, where there is little foot traffic and you want a nice “cushy” feel to the carpet, you may choose a thicker, less dense padding. This might be in a bedroom or an area in front of the TV where your partner sits on the floor to watch football.

Generally, you will have three basic material choices for residential carpet padding: foam, sponge rubber and fiber.

They are all available in a range of thicknesses and densities. For a given thickness, you can compare the ounces per square yard to gauge the density of the padding.

Foam padding, often urethane foam, is my favorite for most residential applications. There are several grades available, but you will usually see what is called bonded foam. It is made of multicolored small pieces bonded together. It typically has fairly good density.

Fiber padding, which you often see under older carpeting, looks like animal hair. There are new types of fiber pads, and some are made from recycled fibers. Fiber pads produce a very firm foundation and may be a good choice for very high traffic areas.

Sponge rubber pads are available in a waffled or flat contour. The waffled design is much more resilient than the flat design. If you choose this type, or can find it on sale, make sure to choose a thin pad. Rubber padding provides the least amount of insulation value for cold floors.

If you want to make the best carpet padding selection for each room of your home, contact the Carpet Cushion Council. It has helpful information on these topics. In particular, there is a pamphlet recommending the proper padding type for each room of your house.

James Dulley is a mechanical engineer, an avid Do-It-Yourselfer and a nationally syndicated columnist with Email your questions to him at Here’s How. The opinions expressed are his own.