The Backing Business: Moisture and acoustical abatement are major focuses in underlayment - Jan 2019
By Darius Helm
Over the last decade or so, several major trends have transformed interior spaces in both the residential and commercial markets, and almost every one of those trends has brought with it an unintended side effect-making spaces noisier. It’s not uncommon these days for the most visually beautiful spaces to be scarred by ugly acoustics.
Pressure is on specifiers and owners to bring down the noise, and they have a wide range of tools at their disposal, from construction material selection and design of the space to acoustical ceilings, textured walls and enhancements of flooring and subfloor systems. In flooring, there’s nothing better for acoustical abatement than carpet, and the deselection of carpet for hard surface flooring is a big part of the problem. But hard surface acoustical underlayments and pads, acoustically absorbent adhesives and other substrate applications can all help to dampen sound transmission.
Carpet backings don’t have the same pressure to provide acoustical solutions, and most of the developments in this field these days have more to do with controlling moisture, eliminating problematic chemistries and materials, and increasing production line efficiencies.
ACROSS THE SECTORS
Noisy environments can be stressful and distracting, and they can diminish well-being and productivity, which is ironic, since many of these acoustical problems are byproducts of developments designed to actually increase well being and productivity.
Open plan workspaces, for instance, are noisier than the cubicle designs of old. Exposed ceilings reverberate with echoes. Hard surface flooring bounces sound around, both amplifying and muddying the acoustics, and also transfers sounds through the floors to the spaces below. Sounds that would have been absorbed by the fabric of cubicle walls and kept in check by drywall instead smack against glass walls and windows and ricochet across the space.
The raw, industrial office design that abruptly became the hottest trend about a decade ago laid bare interior spaces, exposing unfinished ceilings and HVAC systems, tearing down interior walls and ripping out carpet. Early on, though, acoustics weren’t a major consideration, beyond the hope that the pervasive collaborative hum would raise the energy of the workforce.
However, rising above the general din are complaints about all that noise and distraction. And many of the most important commercial interiors trends in the last four years have essentially been attempts to remediate the raucous workspace, like privacy zones, area rugs and hard surface underlayments to quiet and soften spaces, and, most prominently, the use of felt-felt barriers, felt wall hangings, felt furniture and even felt lampshades. (It’s a good time to be in the felt business.)
The education sector faces similar issues. Flexible learning environments, even within classrooms, are designed to facilitate learning, but noise can be distracting to students if it doesn’t support the lesson at hand.
According to Mark Vander Voort, principal and senior vice president at HKS and a specialist in the education sector, sound masking systems are often employed, these days generally through electronic speaker systems-most people describe the sound as similar to soft, rushing air. Elevating the ambient noise level makes conversations at a distance effectively unintelligible.
Vander Voort explains that there is a “radius of distraction” that in most offices and open-plan environments is approximately 30’ to 60’, which means that people within that radius are distracted by those nearby conversations. Ideally, a sound masking system reduces that radius to 10’ to 15’, allowing for isolated islands of sound where people can converse and collaborate without distracting others nearby.
In recent years, restaurants have also become much louder. In “How Restaurants Got So Loud,” The Atlantic’s Kate Wagner describes how restaurants used to be designed to be quiet, with extensive use of drapery, upholstered seating, tablecloths and even carpeting. But that started changing in the 1970s, with design trends stripping away the soft goods for a minimalist look focusing on high-end surfaces. Then came open kitchens-making the space louder and brighter-and the merging of bars and restaurants. “As the bar and dining area began to occupy the same space,” Wagner writes, “their clientele and atmospheres combined, and the result was a lot louder than either one alone.”
Wagner reports that, despite a steady stream of complaints, the trend shows no signs of abating-it’s a more profitable model for a whole host of reasons. There’s even an app (IHearU) that rates the decibels of restaurants through user feedback and helps people find quiet places to eat.
Senior living spaces tend to have more soft surface flooring than the other commercial sectors, at least in the residences and common spaces, but acoustics are still a huge concern because of loss of fidelity and overall diminished hearing among seniors. The most significant problem, according to a study conducted by Salford Innovation Research Centre at the University of Salford in the U.K., is poor speech communication, generally due to background noise and reverberant spaces. And it is well established that the inability to hear effectively reduces social engagement and ultimately speeds up mental deterioration. According to the Hearing Loss Association of America, it can even increase the risk of dementia.
Hospitals also have a massive noise problem, though it’s not really new. But several scientific studies since the turn of the century have revealed a strong link between hospital noise and patient well-being and outcomes, which should come as no surprise to anyone who has ever set foot in a hospital. Hard surface flooring-often sheet vinyl or LVT-transmits sound up and down the halls and through the patient rooms: voices of nurses and doctors and patients in need; the judder of rolling gurneys and carts; the rumble of cleaning machines; the monotonous beeping of vital signs combining in maddening syncopation, competing with frantic alarms. All of this exerts a negative force on well-being, comfort and healing.
The hospitality and multi-family markets share a unique set of acoustical problems. Over the last decade, multi-family units have shifted from carpet to hard surface flooring, mostly LVT. These days, carpet is only in the bedrooms-and sometimes it’s not used at all. And more recently, hotels have started switching away from broadloom throughout guestrooms to a mix of hard surface and broadloom or carpet tile. On occasion, it’s all hard surface with perhaps an area rug for accent.
In these environments, the problem is not so much airborne sound transmission throughout the space, since the spaces are small and private. But impact transmission from the hard surface flooring to the units below has become a major issue. Once the second and third floor of a multifamily property start using hard surface flooring in place of carpet, the vertical transmission of sound between floors often becomes an acoustical nightmare.
Pressure is growing for property owners to solve these problems, but it will become a much bigger issue when occupancy rates begin to slide, and the power shifts to the tenant side of the equation.
There’s also more mixed-use space in the market today-stores, gyms, offices and residential units all stacked up together, all ringing in each other’s ears-which, when coupled with stripped down decors and hard surface flooring, reverberate like drums.
Single-family homes have also become much louder, with most of the carpet confined to bedrooms and sometimes the den, and hard surface over the rest of the space. And considering that households with children and pets (i.e. most households) are already loud and chaotic, increasing the cacophony can be almost unbearable. Fortunately, impact transmission is not a huge problem, because second floors still use a lot of carpet, but airborne sound transmission off those hard floors need to be mitigated, and area rugs often offer the most effective solutions.
In the U.S., there are two different systems of measuring the ability of materials to attenuate sound transmissions through interior spaces-STC and IIC.
STC, which stands for Sound Transmission Class, measures the ability to reduce airborne sound across a space, formalized through ASTM E413 Classification for Rating Sound Insulation. Once materials start to go over STC 40 or so, they are sufficient barriers to muffle loud conversations, and over STC 50 will effectively abate the noise from loud TVs, stereos and the like.
IIC, or Impact Insulation Class, as defined by ASTM E989, relates to how well a floor will reduce the transmission of impact sounds-like footfalls-to the space below the floor. Generally speaking, ratings of IIC 50 are at the lower end of effectiveness, and numbers over IIC 65 offer a high level of impact insulation. Most building codes require IIC 50 or above.
Building material producers often use another system to illustrate sound insulation, Delta IIC, which measures the difference in impact transmission before and after the material is put in place. It’s a practical way of comparing the relative effectiveness of acoustical underlayments.
TOOLS FOR SOUND ABATEMENT
Specifiers have a lot of tools in their arsenal. For sound transmission through the air, there are the felts and other aforementioned acoustical materials. There’s even wall carpet, which these days is mostly used in auditoriums and the like but may well find demand growing again across a widening range of applications in the commercial market. Firms like the U.K.’s Tretford offer a range of acoustical wall coverings, and designers also specify floor carpet for wall applications.
However, for impact transmission between floors, a different set of tools come into play, including a range of flooring materials, though FEI Group’s Graham Howerton, who leads FloorExpo’s MultiFamily Solutions group, is quick to point out that it’s a fallacy to assume that impact transmission between floors is entirely dependent on subfloor and floorcovering materials and installation. In fact, how the building is constructed is the main determinant; the biggest barrier to sound is mass.
Wood frame, steel or poured concrete-all of these materials are far more important in sound transference than the choice of acoustical pad and floorcovering. But construction can’t readily be redone, so the mitigation often has to be provided through flooring solutions. Also, in construction projects it’s generally the flooring contractors who are the last ones in, so it falls to them to remedy any acoustical shortcomings detected during the process.
Some floorcoverings come with their own attached backings-they are common in higher end rigid LVTs on the market, and they’re also used in laminates-which can somewhat deaden the clacking of floating installations. However, the general consensus among commercial and residential flooring contractors is that a separate, unattached acoustical underlayment is much more effective, mostly because it’s a continuous barrier across the entire floor, while attached backs go down as individual sections fitted together on the back of the hard surface flooring, but also because attached backs often don’t use the most effective sound attenuation materials.
Underscoring the point, FloorMuffler, a division of Diversified Industries, is getting ready to launch FloorMuffler Encore LVT, an acoustical product specifically designed to work with direct-attach products, like LVT with an attached underlayment. And among its acoustical products already on the market is Natura Elite, which features 98% recycled fiber content, including from reclaimed carpet and pad. Natura Elite has a Delta IIC of up to 21 and FloorMuffler Encore’s Delta IIC is up to 22. The multifamily sector is FloorMuffler’s strongest market for its acoustical products.
Many acoustical underlayments use synthetic rubber, like SBR, in dense constructions because of its ability to absorb vibrations. Leggett & Platt, for instance, offers dense rubber underlayments for the residential market, like its Whisper Step LVT underlayment and ACI-125, an underlayment for ceramic tile that was introduced a year ago. Whisper Step, with a 22 Delta IIC, is an extremely dense rubber-62 pounds per cubic foot-that’s only 1.4mm thick, and ACI-125 is even thinner at 1.3mm with a Delta IIC of 17. Demand is high for Whisper Step, which also works with rigid LVT, laminate and hardwood, in multifamily applications.
Leggett & Platt’s Sponge Cushion division makes a similar commercial product called dBarrier under the Tred-Mor brand. Tred-Mor synthetic rubber products provide a dense but pliable cellular structure that helps mitigate vibrations emanating from hard surface flooring above to the space below, like footfalls and the movement of furniture.
The firm tested dBarrier in a hotel in Gary, Indiana where the guestrooms were installed with LVT and carpet tile, and guests were complaining about noise. The hotel, which used a grading system for acoustics, put in dBarrier with great success, ultimately validated with 18 months of data and positive guest feedback.
Mapei, the massive Italian firm best known in the flooring industry for its ceramic tile installation materials, like grouts, thinset and mortar, offers a comprehensive range of surface preparation products for every floorcovering type, from carpet to hardwood, LVT and even decorative concrete.
When it comes to impact insulation, Mapei offers two primary acoustic solutions-a bituminous membrane that’s fabric-reinforced with a peel-and-stick application and a reflective layer, going to the market as Mapesound 90 and Mapesonic 2, and a recycled crumb rubber system just introduced last year, called Mapesonic RM. The two systems prevent the vertical transmission of sound in different ways: Mapesonic RM’s rubber membrane absorbs sound, while the other two products reduce transmission by reflecting sound back into the room.
Mapesonic 2, introduced about five years ago, has a thickness of 75 mil (1.9mm), while Mapesound 90, which has been out for three years, is 90 mil (about 2.3mm). Both are used for all types of hard surface flooring. Mapesonic RM is much thicker; it’s available in 5mm and 10mm, ideal for ceramic and stone installations. All the systems have a Delta IIC of 20 or better.
The biggest market for Mapei’s acoustical underlayments is multifamily, along with hospitals, schools and hotels.
DriTac has been in the adhesives business for 40 years and in the acoustical underlayment business for about three years, though it already has a running line of around ten products, including recycled rubber underlayments and closed-cell foam products for double glue applications. Some of the underlayments for rigid LVT feature limited compression and deflection and closed-cell foam of 1mm thickness or less. 8301 Impact, for instance, is only 0.8mm thick but has a Delta IIC of 21. The firm’s thickest products are 10mm recycled rubber for use under ceramic tile and stone, with similar sound ratings.
DriTac’s rubber products tend to go to the commercial market, while its foam underlayments are stronger in residential, including multifamily.
MP Global Products has a wide range of underlayments with acoustical benefits, including VentiLayer, launched a couple of years ago, and its best selling QuietWalk, which is composed of 95% post-industrial content. VentiLayer is made of the same recycled material, but it also offers a layer that allows airflow to vent moisture from concrete subfloors.
Last year, MP Global came out with QuietWalk Plus, which is enhanced with a surface designed to accept glue, enabling its use in glued and nailed installations-QuietWalk works only with floating floors. QuietWalk Plus is ideal for dealers who only want to carry a single SKU. Both have a Delta IIC of 22.
The firm also sources an LVT underlayment for floating and gluedown applications. The product is made of dense SB rubber that’s 1.4mm thick-while QuietWalk is a little over 3mm.
Healthier Choice offers two acoustical underlayment lines, Sound Solution and OmniChoice. OmniChoice, which is solely for acoustics, is a 55 mil (1.4mm) frothed polyurethane that can go under all flooring types. The chemistry is similar to Sound Solution, though it’s somewhat denser and thinner (Sound Solution is about 85 mil or just over 2mm); it’s also available with Vapor Bloc technology. Both have IIC ratings of 73, and OmniChoice offers a Delta IIC of 20 for laminate flooring over 6” slab and 22 for LVT over 6” slab.
While its products are used in commercial applications, most of the demand is from multifamily applications, where it meets the code requirements.
HPS Schönox North America, based in Florence, Alabama, offers a range of Schönox products, including synthetic gypsum, which it uses to make self-leveling compounds. But the firm also offers a unique product called Schönox TS, which it describes as an impact sound insulation layer that also provides heat insulation. The product, which has a Delta IIC of 20 and is about 3mm thick, is a solid sheet composed of cork and urethane granules.
Ideally, Schönox TS is glued to the substrate, then covered with synthetic gypsum, like Schönox AP or APF, so it’s really sandwiched in there. The product has been sold in Germany, where Schönox is headquartered, for several years, and it’s been in the market for two years, where it’s mostly used in multifamily and hospitality applications.
And it’s not just underlayments that work under floorcoverings to reduce acoustical values. For instance, Bostik has hardwood adhesives-Ultra-Set SingleStep2 and Vapor-Lock-that include thickness control spaces made of recycled rubber particles.
According to the firm, the acoustical abatement qualities of the adhesive derive from the different durometer levels of the materials in the adhesive-durometer scales quantify the hardness of compressible materials like polymers and rubbers. Those different hardnesses absorb frequencies differently, and using multiple materials in the adhesive helps capture a wide array of sounds. Both products have a 21 Delta IIC.
The firm also offers a non-sag adhesive for gauged porcelain tile on wall installations, called Bosti-Set, which also features thickness control spacers that attenuate sound.
These underlayments and acoustic adhesives mostly work to diminish impact transmission down through the flooring, but they can do little to reduce the acoustical reflectivity of the hard surface flooring, which bounces sound around the space. The only real solution to both impact transmission and airborne sound transmission is to use carpet. And while such a major trend reversal is probably not in the cards, many in the industry expect to see more carpets and rugs specified for acoustical solutions in the coming years.
Shaw Industries made a smart move with its LifeGuard backing toward the end of last year. LifeGuard, introduced in 2015, is a waterproof unitary backing system-replacing the latex binder and secondary backing-made from a modified version of the firm’s commercial EcoWorx polyethylene backing. What Shaw did was color it baby blue.
It’s just a color…until you unpack it:
• It’s the only colored residential backing system, other than white or a neutral, making it uniquely memorable
• The choice of color communicates the enhanced performance features
• The fact that it is so prominently colored infers added value
• LifeGuard in private label programs will feature the same baby blue, extending visibility beyond the Shaw brand
On top of that, it’s a strategy that’s just about impossible to compete with or to undermine. What are the other big mills going to do? Come out with orange backings? Green? Maybe stripes? Well, that’s one way to signal desperation. Or perhaps they could lobby for tariffs on blue dye.
As Shaw has learned over the last two decades with its plush SoftBac backing, producing a performance backing with a distinctive look can be a game-changer. Retail salespeople will know LifeGuard is a Shaw product regardless of the style name, and it gives them another feature to promote to the consumer.
CARPET BACKING UPDATE
Carpet backings have added new performance features in recent years, and while some of these backings have acoustical attributes, most of the developments have been related to moisture, from preventing moisture from seeping down to providing channels for moisture to escape. And the carpet backing business has also seen the development of new constructions. The three biggest carpet mills, Shaw, Mohawk and Engineered Floors, each have carpet lines with backings that eliminate the use of latex.
While the big carpet mills have their own in-house backing production, a handful of independent producers serve the rest of the market with primary and secondary backings, and they also offer specialty backings to most mills, including those that are vertically integrated.
Independent backing producers took a bit of a hit this year, in part due to the sluggish market, but also because of Engineered Floors and its backing plant in Bridgeport, Alabama. In late 2017, Engineered Floors purchased Beaulieu’s assets, which included the backing plant. At the time of the acquisition, Beaulieu was running the facility at far below capacity, but Engineered Floors quickly ramped it up, significantly reducing how much backing it was purchasing from independent producers. According to sources, running the Bridgeport plant at virtually full capacity has taken about 100 million square yards out of the market.
About five years ago, Mattex, which is headquartered in Dubai with production in Dubai and Saudi Arabia, invested $60 million to build a production facility in Eton, Georgia for woven backings, first just polypropylene backings, then woven PET. Two months ago, the firm announced that it is shuttering production of both polypropylene and polyester woven backings in Georgia and shifting manufacturing back to the Middle East.
In a statement released on November 20, Luc Blommaert, CEO of Mattex Group, said, “After serious thought, the Mattex management team has decided that the most efficient way to service the North American market with fabrics is to put all our production assets into the Middle East.” Blommaert also reported that local market dynamics had forced the firm to re-think its manufacturing strategy.
According to the firm, it will start moving equipment this quarter and through the transition will strive to serve its customers with product shipped from its Middle East facilities.
The leading independent backing producer in the U.S. market is Propex, which has been serving the market for nearly 50 years, originally as Amoco Fabrics and Fibers. And now that Mattex has shifted all of its woven production back to the Middle East, Propex is the only domestic woven backing producer that isn’t owned by a mill or closely affiliated with one.
Traditionally, Propex’s offering has been woven polypropylene primary and secondary backings for broadloom, but seven years ago the firm decided to also go after the growing carpet tile market. At that time, primary backings for carpet tile were spunbonded nonwoven PET, but Propex came out with Isis (now Artis, for obvious reasons) a woven PET backing offering some advantages over nonwovens, including better stitch hold and mendability and fewer dropped ends-and, ultimately, improved throughput.
The last few years have seen an expansion of the Artis program with a range of widths and pick counts. And Propex has also done some custom programs, including a partially exposed Artis backing in a range of metallic colors for Deconstructed Metal, a carpet tile style by Shaw’s Patcraft.
All of Propex’s broadloom and carpet tile backings for the U.S. market are produced at the firm’s facility in Hazlehurst, Georgia, including the Artis woven PETs, which were initially produced at its facility in Gronau, Germany. The firm also has production in Mexico, Brazil, Hungary and the U.K. Global headquarters are in Chattanooga, Tennessee.
While woven primary backings have made inroads in the carpet tile market, most are still manufactured with polyester spunbonded nonwovens. The leader in the market is Low & Bonar, which makes Colback. The Scottish firm has production facilities in Europe, the U.S. and China. Another prominent firm is Freudenberg Performance Materials, which also has a global operation. Freudenberg is headquartered in Weinheim, Germany. Both also pro-duce high performance spunbonded nonwovens for automotive carpet.
When it comes to specialty backing producers, Universal Textile Technologies (UTT) has been a leader in environmentally sustainable systems since 2002, when it partnered with Dow to create a soy-based polyol, which was used to replace a portion of the petroleum-based polyurethane in its backings. The firm’s BioCel and EnviroCel polyurethane backings, with bio-based and recycled content making up 60% of the material, are used in the commercial market. BioCel’s thicker precoat lends itself to higher traffic applications like airports, shopping malls and convention centers, and its moisture barrier drives business in sectors like senior living. EnviroCel’s strongest market sector is hospitality. A non-cushioned product, BioCel Laminate, is often specified in environments with rolling loads, including in senior living.
BioCel and EnviroCel got a little greener in 2018, replacing their limestone and coal fly ash filler with ReMined, a post-industrial limestone salvaged from mining operations through Imerys Carbonates. Also, its recycled PET content, which used to come from drink bottles, now comes from reclaimed PET carpet. The purchase of material from reclaimed PET carpet helps stabilize and support the carpet recycling industry.
A key backing component for broadloom is SB (styene butadiene) latex, which is used to bind the tufted carpet and primary backing to the secondary backing, and the global leader in latex for carpets is Trinseo. Over the last couple of years, the firm has been developing enhancements and alternative chemistries, including a new modified acrylic binder that offers better wet Velcro performance in carpet tile, as well as improved flame retardant binders for tufted broadloom and other applications. Trinseo reports that it recently launched an improved styrene butadiene binder that improves wet strength retention by 25% and increases finishing line speed.
The firm, which was originally part of Dow Chemical, went public on the New York Stock Exchange in 2014. According to Keith Woodason, Trinseo’s global industry development manager for textile binders, “With continued carpet manufacturer consolidation and globalization, Trinseo has begun developing latex products globally from an expanded Technology and Innovation facility in Rheinmünster, Germany that includes new analytical capabilities as well. Product development is being fully supported with textile binder Application Development Centers in Shanghai, China; Samstagern, Switzerland; and Dalton, Georgia, U.S.A.”
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