Carpet Pads, Cushions & Insulating Underlayments
DEAR TIM: It is time for new wall to wall carpeting in my home. The carpet will cover both concrete and wood floors. There seem to be so many different carpet pads. Which is the best to use? Is thicker padding better? What can be done to insulate the floors to maximize comfort and reduce noise? R. M.
DEAR R. M.: The abundance of carpet cushion choices can easily confuse most consumers. By the way, cushion is the politically correct term. Not only are there different material types, most of them are available in varying thicknesses. If you make a mistake, you will shorten the life of your carpet and potentially be uncomfortable.
There are three major types of carpet cushions that most homeowners recognize: fiber, sponge and foam rubber. There are different types and grades within each grouping. Thickness of cushion and weight in ounces per square yard are the yardsticks which allow you to differentiate one from another.
The type and amount of foot traffic in a room determines the type of cushion you should use. Heavy traffic areas, stairwells, and hallways require cushions that are no thicker than 3/8 inch. These cushions should also be dense and heavy. Do not use a thick, light weight cushion in these areas. It will allow the carpet backing to flex too much. This can cause the carpeting to fall apart.
If you want a soft, luxurious feel in a bedroom or other lightly traveled room, choose a 1/2 inch thick pad. To increase the life of the carpeting, choose a high density or weight cushion. Remember, the cushion is the foundation for the carpet. It just doesn't make sense to install a flimsy, inexpensive cushion beneath an expensive carpet.
Carpet cushions have wide ranging insulating or R values. They can range from as little as 0.2 R value to as much as 2.1 R. Sponge rubber pads, believe it or not, tend to have lower R values. Rubberized jute fiber and prime urethane foam cushions deliver high R values. For example, a flat rubber cushion that weighs 62 ounces per square yard has an R value of 0.21. You can purchase a 1/2 inch thick prime urethane cushion that will yield an R-value of 2.1!
To block the cold temperatures, which are conducted through your wood or concrete, you can use an underlayment material. These wood fiber boards are made from 100 percent recycled materials. A 1/2 inch thick panel will deliver an additional 1.2 R value. The boards are easy to install. You simply install a 1 and 1/2 inch wide by 1/2 inch thick border around all walls. This will provide an adequate surface to attach the carpet tackless strip which holds the carpeting in place. The insulating boards themselves can be either glued in place or allowed to float beneath the carpet cushion.
Noise reduction and added resiliency are added benefits that you will experience if you choose to install the recycled carpet underlayment material. This is especially important if the room will house a sound system or giant screen TV with surround sound speakers. Cold, hard floors will be a thing of the past if you spend some time choosing the correct carpet cushion and underlayment material.
Author's Notes :
December, 1998
Several days ago, I received a letter from the Carpet and Rug Institute. Their membership represents about 90% of the carpet manufacturers in the USA. They found this column on my website and wished to offer a few suggestions. Just so you know, the data in the column was provided by the Carpet Cushion Council.
The bottom line is that the carpet manufacturers seem to conflict what the cushion manufacturers say. The carpet manufacturers suggest that the you never use a pad that has a thickness greater than 7/16 inch for any carpet. Thin carpets such as Berbers and other short pile carpets should never have a pad thicker than 3/8 inch.
So, there you have it! Whatever you choose to do always make sure you follow the written carpet installation instructions. If you install a pad that is too thick, it may void any warranty.