A general rule of thumb for most residential carpet applications is to choose cushion no more than 7/16 inch thick and no less than 1/4 inch with 6 pounds per cubic feet density. If the carpet is a berber or a low profile carpet, choose a cushion no more than 3/8 inch thick with 8 pounds density.
Most carpets call for 7/16-inch padding. Choose stiff, stable padding with a thickness of 3/8-inch or less for a low-pile carpet. This includes Berbers, loop pattern carpets and commercial options. Tip: Carpet padding should be replaced when new carpet is installed.
However, all other things being equal, the higher the carpet density, the more durable the carpet will be, and the more pleasing it will be underfoot. Just as a lawn is more luxuriant if the grasses are thick underfoot, a carpet with higher pile density will feel plusher and will hold up better with wear.
The combination of thickness and density is all important as a thick underlay with a low density may not perform well. Typically the thicker the underlay the better quality it will need to be - 9- 7mm is the most common domestic thickness with 11mm often used for luxury installations.
The higher the number, the more durable the carpet. A density rating of 2,000 or more. Density is determined by the thickness of the fibers and how tightly packed they are. The thicker and heavier they are, the better quality the carpet and the less susceptible to crushing.
Most residential carpet requires a pad that is between 3/8 of an inch and 7/16 of inch thick with a minimum 6-pound density rating. However, low-profile carpets, such as berber, should not use padding that is thicker than 7/16 of an inch (3/8 of an inch is commonly recommended).
Most carpets have a face weight somewhere between 20 ounces and 100 ounces, with the average for residential carpet falling somewhere between 35 to 60 ounces.
But if you're looking for something a little softer and more sumptuous, be sure to opt for a thicker product. 10mm works well for stairways and extra thick carpets. However, in most cases, we recommend a 12mm underlay – as this tends to have the best properties overall.
Generally speaking 7mm is about as thin as you want to go unless you have a specialist need for something thinner, but 8-12mm is the band most manufacturers produce carpet underlay with 9-11mm being the most popular products.
At 12mm thick, this is the thickest underlay you can buy for use with carpets. The extra thickness is designed to provide a lovely, comfort feel throughout your home.
I generally recommend a pile height of less than 3/4″ to help reduce the chance of matting and crushing of the pile. Why? A shorter Pile-Height makes for a much more durable carpet, it makes the carpet much easier to clean and makes the carpet more stain resistant and less prone to matting and crushing of the pile.
While rug or carpet pile heights vary, they typically fall into three categories: low (less than ¼ inch), medium (¼ to ½ inch), and high (½ to ¾ inch). Piles longer than ¾ inch aren't quite as common. These types are usually designated as “plush” pile height because the longer the pile gets, the softer the rug feels.
"A higher face weight means more yarn," says Grable, "And more yarn makes for a longer-lasting product." As an example, within one product line the "good-level" carpet has a face weight of 40 oz.; the "best-level" weighs in at 63 oz.
Medium pile – 7mm to 13mm
Medium pile carpets are the Goldilocks of the carpet world.
For residential purposes and installing carpet padding in low to medium traffic areas, you would need a carpet padding thickness of ¼ inch to 7/16 inch. ¼ inch is the minimum that you should get, but it must not exceed 7/16 inch of thickness.
We recommend going no thicker than 11mm for the stairs as anything over this will be very difficult to fit – read our guide on how to fit stairs carpet for more info. 9mm is the optimum thickness, however it can depend on the density of the underlay.
In short, 9mm is generally best for high traffic areas such as stairs and 11mm is best for comfort areas. There are other specifications that need to be observed. So, have a read of the product specifications below for the full range of options when choosing the thickness you need for your Cloud 9 Underlay.
Carpet underlay is an excellent insulation tool for your home. Because it is an extra layer between your carpet and the subfloor it acts as a new insulative layer. This then leads to a reduction in heat loss which in turn will mean you can save money on your heating and energy bills.
Super 8mm Carpet Underlay PU Foam
Super is a good quality PU Foam 8mm Underlay will provide your carpets with a soft feeling underfoot and a good base level protection for your carpet. It will also provide high sound reduction, thermal and comfort properties.
The Extra Step Heavy Duty 6mm is fantastic value for an extremely durable underlay which is guaranteed to prolong the life of any carpet in even the most high traffic areas. As well as being one of the most heavy duty products on the market, it also boasts good sound reduction and heat insulation properties.
The best type of underlay for carpet is PU foam. It is the best option due its many advantages over alternative types of underlay such as its strong heat insulation abilities and the soft underfoot it provides. However, sponge rubber is another solid option.
In general, you'll find carpet across a full spectrum of face weight, somewhere from 20 to 100 ounces. For residential use, most carpet weight settles in between 35 and 60 ounces. A higher face weight does not equal a better grade of carpet.
Most carpets have a face-weight somewhere between 20 ounces and 100 ounces, but the average face-weight for a residential carpet is about 35 to 60 ounces. A higher face-weight does not automatically mean the carpet is a better grade; is a higher quality; is more durable; or is more costly.
Low pile carpet has short fibers that look and feel flat and dense. This type of carpet is easy to clean and durable; it doesn't catch much dirt or debris, and it can stand up to a lot of foot traffic without losing its initial appearance.
The general rule is that carpet padding shouldn't be thicker than 1/2”. The Carpet and Rug Institute recommend padding no thicker than 3/8” for Berber carpets.