Cushioning Underlayment for Carpet and Floating Floors
When selecting a cushioning underlayment for a carpet or floating floor, more may be riding on the decision than you realize. The wrong choice under soft goods can cause the carpet to wear much more quickly, and in the case of hard surfaces it could lead to a complete failure. We spoke with several leading manufacturers to learn how to choose the right product for the right job.
Matt Caldwell, vice president of sales for TredMOR/Sponge Cushion, said while selecting a cushioning underlayment the first thing a contractor needs to determine is the type of application the product will be used in. “Most importantly, is the application residential or commercial? The gauge and density of an underlayment will define its durability and will play an important role in how it manages foot traffic, heavy rolling loads, comfort underfoot and acoustics.”
If there any questions about what density of cushion to use, consult the flooring manufacturer. “Always follow the flooring/carpet manufacturer’s guidelines for installation, which includes the specific type of underlayment suited for their flooring,” Caldwell noted. “Do not use anything thinner or less dense than their specifications. Although some of the hard surface manufacturers demand their underlayment be used, most won’t push back as long as the contractor’s preferred underlay exceeds their recommendations. They too just want to make sure the correct products are used so their floors do not fail.”
The company’s technical product manager, Joel Cartee, added that for carpet cushion, look for products “that have a fair amount of resilience for comfort underfoot, but it also needs to be firm enough to handle foot traffic and pivot points. The right density and firmness will add years to the life of the carpet, especially in heavy traffic areas. Less density contributes to crushing/matting the fiber quicker as there is little to no support.
“Seams can also be an issue when the wrong density is used. A good quality cushion will likely outlast the carpet it’s installed beneath and shouldn’t bottom out in heavy traffic areas like halls and stairs.”
For floating systems, Cartee said to choose “a firm underlayment to support the hard surface installed upon it. A less dense and thicker product could affect the structural integrity of the tongue and groove, causing the floor to separate due to deflection or bounce in the floor. Lesser products in density can bottom out and lose the acoustic value they were attempting to address. However, it does need to be thick enough to bridge imperfections in the substrate to eliminate deflection. With hard surface, the wrong underlayment can cause a total failure of the system.”
Cartee stressed that the best underlayments do not just offer comfort underfoot, but peace of mind as well. “A proper cushion can make a floating floor feel as if it’s nailed or glued down. Denser cushions have a higher IIC (Impact Insulation Class) rating, deadening the sound in the room when walked on. The denser the cushion, the better the R-value for radiant heated floors as well.
“A denser cushion will extend the life of carpet up to 30% to 50%, adding five to 10 years of life. And in a floating surface install, a good quality pad can be used again because it will not bottom out.”
According to Wade Verble, DriTac vice president of business development, understanding the specified sound ratings for applicable building codes is crucial. “Manufacturers will typically have sound ratings listed on product labels or their website. You can match those ratings with the ratings specified by the architect, specifier, contractor or builder. If the installer still cannot get the answers he needs, he can always submit a Request for Information (RFI) to the specifier. This can assist the flooring contractor in attaining acceptance of the product prior to installation. Failure to use the correct underlayment can result in excessive sound emissions—in many cases, the floors will have to be removed and replaced with the specified product.”
The proper underlayment will offer other benefits as well, Verble noted. “The installation may require that various floor types with differing heights match up and conform well at the point of transition. Knowing the thickness of the cushion used will assist with planning transitions to dissimilar products. In many cases, this will eliminate the need for costly floating and expensive transition moldings.”
He added, “DriTac offers a system that also includes moisture protection. It can reduce the amount of sound transmission from floor to floor. Additionally, underlayments do have some thermal and insulation advantages. Floors installed with underlayment over concrete tend to be much warmer in cold weather climates.
“In some cases, the underlayment can ultimately be more cost-effective to the consumer. Most underlayments can eliminate or reduce the amount of floor prep needed. This can improve the appearance of the finished floor covering product by producing a flatter, cleaner-looking floor.”
Dale Asp, national business development manager for the Impacta Flooring Division of Sound Seal, stated that contractors should understand the different choices of cushion available to go beneath a floating floor. “Some floating floors have a locking system that may not be compatible with all forms of underlayment/cushions. If they are in doubt on whether it is the correct choice, they should ask the retailer/dealer they are purchasing it through. They can also contact the flooring manufacturer directly as well as the manufacturer of the underlayment/cushion to get their opinion. Failure to supply the correct or acceptable underlayment/cushion could result in a failure of the locking system or damage the floor structurally.”
The extra homework will pay off in the end, Asp stated. “In some cases the underlayment/cushion can actually allow the floor to wear better under foot traffic than if it were installed directly on the subfloor.”
Jim Wink, vice president of sales and marketing for Foam Product Corp., said for carpet cushion his company “only manufactures a high-density commercial/hospitality carpet cushion. We do not manufacture residential carpet cushion because the residential cushion tends to be a low-density quality, so we stay with our highest-quality commercial cushion.
“In the commercial/hospitality market, a high-quality dense cushion is needed to support the heavier foot traffic and extend the life of the carpet. A low-density cushion will bottom out and cause the carpet to wear prematurely.”
S.D. Raney, technical services coordinator for Schönox HPS North America, said when choosing a cushion for a floating floor, pay attention to “the certifications achieved, especially the VOC level; the makeup of the product and what are the contents? Has it been EN 12 529 tested—how heavy a load will it endure before indentions will not ‘pop back’ within 24 hours? What is the adhesion strength of the product, or what will adhere to it?”
Caldwell: “TredMOR ‘dBarrier’ is our new versatile underlayment developed for LVT/LVP, but can be also used for rigid core technology, laminate, engineered and solid hardwood. It can be double glued, single glued, nailed/stapled or used in floating applications. Made from dense SBR rubber, it’s rated extra heavy for commercial but has gained momentum in the residential sector. It not only adds a nice feel underfoot; it has outstanding acoustic values that address these two issues associated with hard surface.
“TredMOR ‘Modular PVI’ Carpet Tile Cushion was developed to address the acoustic issues associated with direct glue carpet in vertical applications (multi-family and hotels). However, sound was not the only issue we’re trying to correct. Modular PVI cushion also adds comfort and reduces fatigue from long hours of standing in commercial/office settings. It is rated extra-heavy for commercial and will handle heavy foot traffic along with continuous rolling wheel traffic.”
Verble: “DriTac has unveiled two new underlayment systems: DriTac 8302 Double Impact for wood and laminate floor installations and DriTac 8301 Impact for resilient floor installations. Both low-VOC products provide enhanced acoustical abatement properties and provide a total sound reduction system (SRS) with dual force, silent fuse technology when used with approved DriTac flooring adhesives. Available for the first time in the market, DriTac’s SRS also offers moisture control properties, less risk and a lifetime warranty from one trusted company.”
Asp: “Cerazorb 3, 5 and 10 mil [can be used] under ceramic tile and stone as well as with floor heating systems. Our new sports floor called ProBase Sport is available in three profiles: rolled goods, interlocking and thick tiles.”
Wink: “Our Dynathane carpet cushion is a 16 lb. high-density product in thicknesses of 1/4” and 3/16” for all sectors of commercial applications. Dynathane is a 100% high-density polyurethane foam, compared to heavy rubber and lightweight fiber cushions.
Raney: “Schönox TS is an impact sound and heat-insulating underlayment.”