LEARNING OBJECTIVES

After reading this article, you should be able to:

• Identify how rubber flooring’s limited cleaning and maintenance requirements translate into a high life-cycle cost value.
• Differentiate how rubber flooring meets stringent IAQ requirements, as compared to other flooring types.
• Identify common recycled content within rubber flooring and its end-of-life recyclable uses.
• Appreciate the level of foot, leg and back support afforded by rubber flooring, as well as slip prevention.

Once limited to weight rooms and playgrounds, the virtues of rubber flooring have catapulted the product into a wider variety of applications including healthcare, education, corporate and recreational facilities.

With limited maintenance needs, a long life span, low life-cycle costs, underfoot comfort, good sound absorption properties and excellent slip resistance, rubber has become a more compelling resilient flooring choice. Made from recycled materials and being recyclable, in addition to meeting high IAQ standards, rubber’s sustainable qualities are impressive as well.

And when it comes to aesthetics, rubber has come a long way. “Once available in every shade as long as it was black, manufacturers now produce rubber flooring in scores of different colors,” says Stephen Ashkin, president, The Ashkin Group, Bloomington, Ind. “Some colors can be transitioned, fading from one color to another adding unique interest and design flexibility.”

Keep it Clean

Perhaps one of rubber flooring’s biggest claims to fame is the fact that it requires considerably less cleaning and maintenance than other flooring types. Essentially, there’s no finishing, waxing or sealing. Just a daily sweep and mop, and if desired, a one-step condition and polish every couple of weeks or so. The polish lends a nice sheen and makes the floor appear as if it’s been waxed.

In fact, Sylvia White, MS, manager of custodial services, Southern Polytechnic State University, Marietta, Ga., estimates that the necessary time and effort to maintain rubber flooring systems is about half of that required by other materials.

At this private college, rubber flooring is installed in many of the entryways: the police department, the wellness center, weightlifting area and some vending machine locations.

Meanwhile at Metrolina Regional Scholar’s Academy in Charlotte, N.C., rubber flooring is used extensively throughout the school in assorted colorful patterns and designs.

“We chose this flooring because we are trying to support a strong environmental ethic for our school community. The idea of no stripping with chemicals, waxing or needing to use other unpleasant cleaning products was a major determining factor in our selection of the rubber flooring,” says academy director Marie E. Peine, Ph.D. “The flooring makes the building look and sound so much brighter.”

Similarly, at Urge Fitness in Ewing, N.J., ECORE rubber flooring in the free weight and cardio areas, spin class rooms and general exercise room lends a fresh look to the fitness center, especially after cleaning.

“We just go in there, hit it with a mop and one, two, three…once the water hits, it looks like brand new. It couldn’t be easier,” says Shayne Michaelis, director of operations, Urge Fitness.

As far as the cleaning itself, White recommends microfiber broom and mop products as they require considerably less water and the floors dry faster.

“The microfiber product grabs the dirt and then releases it when you wash the mop,” she explains. “Consequently, you can get a lot of uses out of microfiber.”

And because rubber has a nonporous and dirt-repellant surface, all the dust and dirt stays on the top, so it’s easier for the microfiber to pick up. This quality also makes rubber an ideal application for fitness rooms as the area can still be properly cleaned without having to move the heavy exercise equipment.

While Ashkin agrees that these flat mops are an eco-friendly option, he also notes that in cases where the rubber floors have a textured, studded finish, a traditional string mop may be more practical for better ease of cleaning.

In a similar vein, studded or heavily textured floors can make machine buffing more challenging as dirt and soil tend to get trapped around the studs or within the texture.

“A conventional rotary machine with a pad may be able to deep-clean the floor and remove these soils, but in some cases a cylindrical brush machine is preferable,” he says.

At the same time, Ashkin prefers vacuuming, claiming that a backpack vacuum cleaner with a multi-stage air filtration system is frequently a significantly more thorough and environmentally preferable procedure. This way dust and contaminants won’t be swept up into the air and negatively impact the facility’s IAQ.

In terms of actual cleaning products, Green Seal-certified cleaners are a great alternative to VOC-intensive chemicals.

For example, ECORE’s Green Seal-certified E-Cleaner can actually be poured directly down the sink after use.

Meanwhile, other manufacturers, such as nora, offer their own comprehensive cleaning system that combines water, an auto-scrubber and scrubber pads.

“The pads incorporate industrial diamonds to provide a choice of three different abrasion levels,” says Amy Bostock, manager, marketing and creative services, nora systems, Salem, N.H. “With regular use, the system increases the floor’s resistance to scuffing and staining while removing surface damage.”

Although White notes that the good cleaning products are relatively expensive, she finds that they’re worth the value as they maintain the cleanliness and appearance of the floor.

Looking at Life Cycle

When looking at rubber solely from a first-cost perspective, rubber flooring systems are among the more expensive. As a point of reference, rubber can run as much as three times more than vinyl composite tile. However, rubber’s minimal cleaning requirements make a big difference when looking at the big picture.

“Unlike other flooring types, rubber does not need to be waxed and stripped as part of the cleaning process,” says Bostock. “As a result, building owners save money on the materials involved in this process and on the labor required to perform them.”

As a matter of fact, a Florida Department of Education study found that with some flooring materials, the expense of operating and maintaining the floors was costing just about as much as replacing the entire floor every year, which surprisingly the schools were actually doing because budgeting for floor replacement was easier than allotting funds for extensive maintenance.

Consequently, the general consensus is that rubber flooring is one of the best value solutions out there.

“There are few floors that are as durable or can last as long as rubber. Maintenance requirements of rubber flooring are minimal and unlike carpet, rubber flooring will rarely appear soiled,” says Ashkin.

Backing this up, a 15-year study tracking the total average cost of maintaining 1,000 square feet of VCT, sheet vinyl, rubber and carpet found rubber to offer the best life-cycle value. Although the data published by the Florida Hospital’s Office of Design in 1998 is somewhat dated, the research found that it ran twice as much as the original product cost to maintain a rubber flooring system for 15 years. As compared to four times the original cost for carpet, six times VCT’s first cost and seven times the original cost of sheet vinyl, rubber clearly stood out as the best investment.

Referencing another study—this one conducted in 2007 by an interior designer at Burt Hill—Doris Witte, EDAC, NCIDQ, professional associate, senior interior designer, HDR Architecture, Omaha, points out that the life-cycle costs of bamboo and engineered hardwood rivaled that of rubber, however, there are certain settings, such as healthcare spaces, where wood would seldom be used. “In combination with the other features of rubber, this is the best choice for many healthcare settings, labs and pharmacy spaces,” she says.

In this particular study, the installation cost for rubber was set at $6 per square foot, as compared to $12 for both bamboo and hardwood, or $1.45 for VCT. After factoring in material and labor costs for a period of 15 years for a 1,000-square-foot installation, bamboo came in at $13,500 in total costs, with rubber and hardwood costing $15,000 and VCT with a total price tag of $46,450.

In another more recent study conducted by the Center for Health, Environment and Justice, a number of recycled rubber products were compared to vinyl, cork, linoleum and non-chlorinated polymer. Although four types of rubber were studied in this life-cycle cost analysis and presented a range of results, generally speaking, rubber was one of the highest total cost values over the course of 20 years when taking into account the initial cost of material and installation, annual maintenance costs and the expected product life span.

For example, the most pricey first-cost recycled rubber product ran $11.70 per comparative unit and cost $24 to maintain for a total cost of $487 over the course of 20 years. The closest contender was cork at $7.25 for material and installed cost, $25.70 in annual maintenance costs and $518 for the 20-year total cost. Otherwise, linoleum, while offering a significantly less first cost of $5.50, ran $33.30 in annual maintenance expenses, amounting to $669 over 20 years. And vinyl, at $2.65, but with only a 15-year life span, as compared to 35 years for rubber, cost $52 to maintain annually and had a significant 20-year total cost of $1,044.

In summary, Megan Capo and Jennifer McLaughlin, IIDA, with RTKL’s Workplace Interiors Group, Baltimore, suggests, “Rubber flooring’s homogeneous construction also provides a natural resistance to damage from gouges, scuffs, cigarette burns and chemical spills. When you compare this with the inherent problems of other floors such as cracking, moisture and bacteria absorption, hardness and high cost repairs, rubber flooring is relatively maintenance free, affordable and a much more user-friendly choice.”

IAQ IQ

Yet another area where rubber shines is in the category of air quality. Containing no polyvinyl chloride, plasticizers, halogen, limestone or other additives, this means that there is no release of toxic halogenated dioxins or furans, and hydrochloric acid would not be produced in the event of a fire.

Also, the fact that no stripping or waxing is required for maintenance means that the airborne chemical off-gassing from these cleaning processes is fully avoided, not to mention the chemical-filled wastewater sent to the sewers and streams.

Putting this into perspective, Ashkin estimates the emissions from cleaning and maintaining most flooring surfaces as 10 times greater than emissions coming from the flooring material itself, as most products release more than 95 percent of its emissions within its first few months following installation.

“Furthermore, rubber flooring provides a dense homogeneous surface that can actually prevent the penetration of bacteria as long as the floor is maintained regularly with appropriate disinfectants,” notes White.

Boosting this quality even further, some companies offer rubber flooring with antimicrobial properties for both cleaner floors and better IAQ, and some manufacturers such as ECORE have incorporated a “green sealing” option as part of the production process for selected products, making them even more impervious to dirt and stains, according to Bo Barber, vice president of sales and marketing for ECORE in Lancaster, Pa.

Along these lines, Capo and McLaughlin also point out that when rubber flooring systems are seamlessly installed, this further prevents bacteria growth, offering a big advantage in certain environments such as healthcare.

To help specifiers stay on top of things, there are a number of IAQ-related product certification programs providing the necessary transparency when it comes to air quality.

For example, a few manufacturers including Johnsonite have tested their rubber flooring systems to strict California-based IAQ emission requirements in order to receive FloorScore certification from the Resilient Floor Covering Institute. Also, in Johnsonite’s case, its rubber products have also been tested to CA01350 as it pertains to schools and offices.

Related to FloorScore, Joe Visintin, product manager, Johnsonite, Chagrin Falls, Ohio, explains that NSF/ANSI 332 Sustainability Assessment Standard for Resilient Floor Coverings offers a method of tracking incremental changes to a products’ sustainability profile which is something that FloorScore looks at.

“As a part of this process, total volatile organic compounds are measured and must show equal or better results than the previous year,” he says.

Yet another certification program which Johnsonite embraces is the Cradle-to-Cradle (C2C) process for its traditional rubber tiles and treads. C2C evaluates the chemical components of a product’s ingredients and assesses their effect on human and environmental health, as well as their ability to be recycled or composted.

The well-known GREENGUARD Indoor Air Quality program offers a regular certification and a certification for children and schools for products which meet the GREENGUARD Environmental Institute’s strict emission levels and ongoing testing requirements.

As such, nora floorcoverings carry these certifications in addition to the Blue Angel eco-label. Originating from Germany, the Blue Angel is the world’s oldest eco-label and includes strict emission requirements as part of its respected certification criteria.

Yet another well known IAQ-related standard is the stringent criteria established by the Collaborative for High Performance Schools, as well as the State of Washington, which carries the highest state standards nationwide. ECORE’s recycled rubber flooring meets the criteria for both of these.

Although rubber flooring products generally have a very good reputation when it comes to low-VOC off-gassing, the California Public Health Institute did perform a study in 2010 which found that some manufacturer claims may be too good to be true. In particular, the Tire-Derived Rubber Flooring Chemical Emissions study revealed that both tire-derived rubber and new rubber flooring products do emit a number of VOCs—which ranges between different products—and includes xylene, butylated hydroxytoluene, ethylbenzene, toluene, formaldehyde and acetaldehyde. From this list, benzene and carbon disulfide were found to be above the health threshold in one or two samples while other chemicals do not yet have health-based standards, so it’s difficult to assess their health impacts.

Based upon these findings, the institute recommends that exterior products not be used indoors and that ample pre-occupancy “flush out” time be incorporated into the project to clear the air prior to occupancy. In addition, the institute would like to see more refinement and testing of rubber-based flooring products moving forward.

Support and Safety

As a soft and flexible material, rubber is known to offer a higher level of underfoot comfort and support. For example, teachers or medical staff who are on their feet for long periods of time will experience less stress on their feet, legs and back, especially when compared to concrete, ceramic or VCT, says Visintin.

In fact, Witte believes that underfoot comfort—specifically shock absorption and good foot support—are one of rubber flooring’s best features.

Comparing rubber flooring performance to tires on the road, Barber explains, “Tires are flexible, which helps them to bond to irregularities in the surface of a road, providing higher friction, which helps tires grip the road better. This same philosophy holds true for rubber flooring—it’s flexible and has excellent slip-resistant properties.”

Slip resistance itself is measured by determining the coefficient of friction. To give specifiers an idea of how a product measures up, a manufacturer’s specification and/or technical data should provide ASTM F141 comparisons.

“The most commonly used test is the James Test which establishes a minimum value of about 0.5, but not all flooring materials are tested and there is no consistency for testing,” notes Witte.

At the same time, it’s important for specifiers to be aware that such a test should be conducted by an independent lab and require that finishes such as wax be applied prior to testing. Generally speaking, most rubber flooring systems will do well on this test and frequently meet Occupational Safety and Health Administration recommendations for slip resistance.

In fact, Capo and McLauglin have seen many rubber flooring products offering between .80 and .90 slip resistance, which surpasses ADA recommendations for flat surfaces.

“In addition, rubber flooring is a nonconductive material—giving it notable antistatic and shock absorption properties,” they explain. “Because of this, it could make an ideal solution for rooms with large amounts of static buildup.”

Of interest is the fact that 55 percent of slip-and-fall accidents are caused by flooring conditions, according to the Floor Safety Institute, and falls account for more than eight million hospital emergency room visits, which is the leading cause of trips to the ER at 21.3 percent.

Furthermore, the incidence rate of lost workday injuries from falls in hospitals is 38.2 per 10,000 employees based upon U.S. Bureau of Labor Statistics. Even more compelling is the fact that according to the Consumer Product Safety Commission, floors and flooring materials directly contribute to more than two million fall injuries every year.

Obviously, the upshot of all these statistics is the fact that slip prevention is of major importance.

Incidentally, U.S. Bureau of Labor Statistics also report that the frequency of fall incidents in hospitals is actually greater than all other private industries combined, at 20.1 per 10,000 employees, making an even stronger case for rubber in healthcare applications.

Offering even more traction, floors can be specified with studs or risers which minimizes the risk of falls even when the floor is wet.

A couple of additional metrics which are used to measure fall protection include compression, which is the extent which the flooring caves under repeated weight impacts, and the flooring’s resistance to head injury, per ASTM 1292. By applying Maximum Deceleration, known as g-max, and Head Injury Criterion, this testing ascertains whether the flooring passes or fails to cushion and absorb the impact, to a certain extent, of a dropped object or a person falling down and hitting their head.

A for Acoustics

Moving on to acoustics, the unique properties of rubber also make it a phenomenal sound-absorbent material.

“With NRC values ranging from 0.05 to 0.15, rubber flooring can contribute to creating a comfortable acoustic space significantly more than other hard surfaces such as tile or terrazzo,” reports Sharon Ho, INCE, acoustic engineer, ECORE.

In addition, its natural elasticity reduces sounds from footsteps and dropped items, as well as dulling sound transmission between floors.

In fact, hospitals and office buildings located next to noisy warehouses have been known to specify rubber flooring for acoustical purposes, and according to Witte, some rubber flooring products even offer the same acoustical performance as carpet, as verified by testing.

“Rubber is among the best materials to use for sound and vibration isolation,” confirms Ho. “Rubber floor underlayments provide a resilient break between otherwise stiff elements and connections such as concrete slabs, ceramic tile thinsets and thick nails. This makes a floor-ceiling assembly less efficient at transmitting sound and vibrations from impacts on the flooring above to the space below.”

Generally speaking, the testing procedure involves using a tapping machine to produce a series of impacts on the floor and then measuring sound transmission levels to the room below. In terms of published results, some studies are performed on rubber with a wood subfloor, per ISO 140-8, and others use concrete subfloors, per ASTM E2179.

Naturally, Witte points out that the use of thicker rubber flooring—i.e., 3mm or 2mm—along with an acoustical backing will enable higher acoustical performance.

As such, Bostock reports that noraplan acoustic rubber flooring has been tested to reduce footfall sound by up to 20 dB for a perceived reduction of 75 percent.

Recycled Rubber

Not only are many rubber flooring products made from assorted recycled materials, but many have a number of interesting end-of-life applications as well.

For example, nora products reuse production scraps such as die-cut trim and sanding dust, but perhaps even more interesting is the fact that they are then recycled and used in landing mats, industrial and stable mats, and coverings for sports arenas.

“They are also granulated and become part of the raw material base of new rubber flooring products as high-quality fillers and decorative color speckles,” says Bostock. “And since they contain no toxic substances, nora floors can be disposed in landfills.”

Meanwhile, ECORE runs a Redeux Reclamation Program and Johnsonite has a similar ReStart program which collects uninstalled commercial rubber—as well as vinyl and linoleum tile, sheet, wall base, accessory and tread-cutting—so that the materials can be repurposed for other products or uses. Johnsonite will also take back unglued rubber tiles from a job site and send them on to a supplier who grinds them to dust for use as filler in auto parts.

Such take-back programs are important to end-users such as Christian Miller, CFM, director, property management, YMCA of Greater New York, who manages 25 YMCAs in the New York metropolitan area. In these facilities, rubber flooring is used in the multipurpose rooms, cardiovascular centers, weight rooms, wet area locker room spaces and outdoor park areas. In fact, a big selling point for Miller is when companies take back and recycle the YMCA’s used rubber.

As far as recycled content in Johnsonsite products, Visintin explains that the company’s CorkTones Rubber Tile and Treads contain 2.5 percent rapidly renewable cork taken from pre-consumer waste stream materials and the company’s Eco-Shell with Cork Rubber Tiles and Treads contains dust made from the annual walnut harvest.

 “Additionally, our SlideLock modular flooring installs easily without adhesive and can be quickly removed, replaced, repurposed or transported so flooring doesn’t have to change just because a space or location does,” he notes.

Similarly, ECORE’s rubber flooring is made from a reclaimed waste stream, which is mostly tires, but also incorporates post-industrial manufactured flooring and roofing membranes. In fact, ECORE claims to be North America’s largest consumer of recycled scrap-tire rubber, reusing more than 80 million pounds of material each year to produce rubber flooring.

Mostly utilizing tractor trailer tires, the old treads are grinded, screened and separated to remove contaminants. The metal debris is collected and sold for reuse in other applications, while the remaining rubber crumb is used for new flooring products.

Disputing the claim that there are IAQ risks associated with using reclaimed waste material, Barber states, “This is simply not the case. While we are taking an unknown waste stream and reusing it, the risks associated with this are negligible. We have learned to refine recycled rubber to the highest standard.”

In terms of rubber itself, Capo and McLaughin point out that the process of removing sap from the tree doesn’t require cutting down the tree, nor does it damage the tree. On the contrary, rubber trees are a sustainable, rapidly renewable resource that naturally generate more sap.

As noted, rubber flooring is often chopped and shredded and then used in a variety of ways such as landscaping mulches, playground surfacing and rubber crumb for athletic fields.

“When used as landscaping mulch, recycled rubber flooring is considered safe and harmless to plants. It also lasts longer than organic materials. And compared to traditional landscaping rock, it provides more volume with less than half the weight. This reduces shipping costs and labor load,” say Capo and McLaughlin. “In addition to the above, recycled rubber flooring is also being combined with re-binders to make Olympic weights and concrete block for pavers.”

Buyer Beware

As wonderful as rubber flooring is, there are a few sticky points that specifiers and end-users must be aware of.

For example, because rubber tends to be a thicker floor, Miller points out that this will sometimes require adjusting the floor’s thresholds. “In some cases, we purchased edges in yellow because of the floor height difference, so it’s not a tripping hazard.”

And although some rubber flooring doesn’t require glue for installation, for the products that do, the process of removal can be challenging. “When you pull it up, it tends to separate and you have pieces that don’t come off completely, which ultimately requires a good floor scraping,” reports Miller.

Furthermore, White points out that sharp or heavy objects can dent the rubber and cause it to split, and once you have to start repairing portions of the floor, this can be costly. Similarly, some cleaning chemicals and metal floor scrapers can also damage the floor.

“You need to properly train staff to maintain this product because it can be damaged easily and all it takes is one little mistake,” she advises.

Offering some additional advice, the International Association of Certified Home Inspectors (InterNACHI) notes the following rubber limitations:

• Rubber is a flammable material and although different grades of fire-retardant rubber flooring are available, they are more expensive products.
• Interactions with light, heat and some metals will cause rubber to oxidize and turn brittle.
• Exposure to inorganic fillers will deteriorate rubber flooring and dull its color.
• Interactions with oil, fatty acids, petroleum-based products, copper and solvents can cause softening and staining.
• Rubber tiles are prone to moisture damage at the seams, which may allow additional moisture to penetrate into the subfloor.
• Rubber floors made from recycled tires have a certain odor which is harmless, but to some may be unpleasant. Some manufacturers recommend their recycled rubber floors not be installed in enclosed, unventilated spaces.

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