With hundreds of products on the market, choosing the right underlayment for your unique application can seem an impossible task.
First, let’s start with the basics.
Underlayment is a thin foam pad measured in different thickness’ and typically made of polyethylene or polypropylene. Most laminates require an underlayment for installation, and some even come with underlayment attached to the planks themselves! Don’t confuse underlayment with moisture or vapor barrier. Think of vapor barrier as the shoe that will keep your foot dry, while underlayment acts as the sock to provide a comfortable break between the floor and the sub-floor. Floating floors can’t be affixed to the sub-floor because they need room to expand and contract with the humidity and climate changes.
Picking the proper underlayment depends on several variables, like sub-floor, comfort level, thermal ratings and noise reduction. Yup, underlayment may provide some sound deadening depending on rating, but that will come later.
A concrete sub-floor, as most people have in Frisco, requires a vapor barrier below the underlayment to prevent moisture from seeping from the slab into the laminate. You wouldn’t want your beautiful new floors to start lifting and buckling at the seams! Some products combine the features of a moisture barrier and underlayment, making installation even easier. These products typically have a label of 2 in 1. Check with your contractor to see if this option works for you and your budget.
Sounds like a horse in your house
If you are putting floors in your new second story apartment or a wide-open loft, consider an underlayment with a higher Sound Transmission Class (STC) rating or Impact Isolation Class (IIC). The STC rating is used to classify the loss of sound in the air and, in turn, the effectiveness of your floor’s sound deadening, while the IIC rating measures impact sound. We’ve all had a noisy neighbor clomping like a horse in the apartment above us. The higher the STC or IIC rating, the better the noise reduction performance. Also, if you have an HOA, check your HOA agreement for any STC rating guidelines they may require, most building codes require a minimum of STC or IIC 50. These tests can be misleading because there are currently no constant parameters. Manufacturers have been known to STC/IIC test their underlayments with thicker concrete sub-floors or soundproofed ceilings. In response to the disparate results, the Delta IIC test was created. The Delta IIC test measures the sound of impact with a single subfloor, usually 6” of concrete. The test is then repeated with the underlayment installed. The measurement is the result of the difference between the two tests. So if the STC rating seems unnaturally high, say 60 or above, ask for Delta IIC rating results, the higher the better. Ask your contractor or flooring professional if acoustic dampening is something you should be concerned about.
Keeping your Toes Toasty
R-Value. No, it’s not some crazy term you’ve forgotten from high school algebra. R-value, or thermal rating, is the measurement of a material’s ability to retain heat. The higher the R-value, the better the insulating power. An underlayment with a high R-value can help keep your toes toasty during the winter, but if you plan to add radiant heating system during installation, the high R-value may prevent your radiant heating from working properly.
Also, keep in mind that the R-Value of the flooring itself varies greatly, based on material and thickness. A laminate floor that has a thickness of 12mm will typically have a better R-Value than a laminate that is only 8mm thick. The quietest laminate installations use a combination of a 12mm product and a great quality 2 in 1 pad.
With nearly every flooring manufacturer providing their own brand of underlayments, all with different ratings and uses, we hope this information has helped to educate you to make the best decision for your home.
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