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Recycling Program Adds to Rubber Flooring’s Environmental Advantages

Well-known for its life-cycle value and durability as commercial flooring, a final challenge— how to recycle it—has been addressed, diverting thousands of tons from landfills.

By Kenn Busch

Well-known for its life-cycle value and durability as commercial flooring, a final challenge— how to recycle it—has been addressed, diverting thousands of tons from landfills.

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Rubber flooring was once relegated to general utilitarian duties. Available mostly in plain grays and browns, it was hidden in back stairways, back hallways and utility rooms. Its durability and performance are exceptional, but it just wasn't "pretty" enough for the public areas of commercial buildings. And the typical round-disc surface profiles weren't conducive to rolling carts or chairs.

Much has changed in the last decade. Manufacturers have introduced smoother profiles in fashionable colors and designs that coordinate with other interior materials and finishes—and rubber flooring's acceptance has grown exponentially, particularly in critical applications like health care and education, but also in many other high-use commercial environments.

The reasons for its growing popularity are numerous. Rubber floors:

  • Make seamless installations possible—perfect for environments where bacteria and infections are a threat, and for spaces that require frequent and intensive cleaning
  • Can be manufactured with antimicrobial properties
  • Interiors & Sources' Continuing Education Series articles allow design practitioners to earn continuing education unit credits through readiong articles published by Interiors & Sources. Use the following learning objectives to focus your study while reading this article. To receive one hour of continuing education credit (0.1 CEU), read the article and then log in to take the test associated with this article.

    After reading this article, you should be able to:

    • Discuss the potential LEED benefits of specifying rubber flooring.
    • Explain how rubber flooring differs from other rubber products.
    • Understand the process of recycling rubber flooring.
    • Discuss the uses and applications of recycled rubber flooring.

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    Have excellent slip resistance, exceeding ADA recommendations for slip resistance on flat surfaces
  • Offer a resilient surface that reduces the potential for injury in the event of a fall, and minimizes leg and back fatigue
  • Are dimensionally stable
  • Are very sound absorbent
  • Resist heavy impact loads
  • Resist cigarette burns and chemical spills
  • Are easy to maintain (no waxing required)
  • Have natural resistance to damage from gouges and scuffs because of their homogeneous construction
  • Have superior color uniformity compared to other materials
  • Offer unlimited custom graphic and design options
  • Create no health or environmental concerns

Some rubber flooring producers have earned FloorScore certification. The FloorScore program, developed by the Resilient Floor Covering Institute (RFCI) in conjunction with Scientific Certification Systems (SCS), tests and certifies flooring products for compliance with indoor air quality emission requirements adopted nationwide. A flooring product bearing the FloorScore seal has been independently certified by SCS to comply with the volatile organic compound (VOC) emissions criteria of the California Section 01350 standard.

These flooring products qualify for use in high-performance schools and office buildings. Products with the FloorScore seal have passed a third-party certification process and are recognized as contributing to good indoor air quality in order to protect human health. Products bearing the FloorScore label also meet the indoor air emissions criteria of the Collaborative for High Performance Schools (CHPS), the LEED Green Building Rating System, and the Green Guide for Health Care.

For many, rubber flooring's biggest selling point is probably its lifetime maintenance cost—the lowest of all major flooring options (see sidebar). It can last and look good for a very, very long time, which is why it often replaces or is specified over VCT, vinyl sheet goods and linoleum. Regular cleaning with an auto scrubber will bring out rubber's natural sheen without the need for stripping and waxing. Couple this with the material's inherent resistance to damage, and you've got a floor that's much more likely to "ugly out" long before it wears out.

This level of durability was once a mixed blessing. When a rubber floor was finally removed, there were no viable recycling or reuse options for the old flooring material, primarily because rubber floors are generally glued down with very strong adhesives that are difficult to remove from the material when it's pulled up—and the presence of these adhesives on the material limits reuse options. Landfilling used to be the only option.

Rubber Flooring + LEED

Rubber flooring has long been recognized as an environmentally friendly choice, and is helpful in garnering LEED credits. Natural rubber, of course, is a rapidly renewable resource, and some products use recycled rubber and cork content. The introduction of the industry's first recycling program adds MR 2 (Materials and Resources, Construction Waste Management) credits to the mix.

Here's a rundown of the potential LEED advantages to specifying rubber flooring, adapted from the USGBC Green Building Rating System for Commercial Interiors:

  • MR 2.1/2.2 NC/CI – Construction Waste Management, Divert 50 Percent (for 2.1) / 75 Percent (for 2.2) from Landfill = 1 Point
    • Intent: Divert construction, demolition, and packaging debris from landfill disposal. Redirect recyclable recovered resources back to the manufacturing process. Redirect reusable materials to appropriate sites.
    • Requirements: Develop and implement a construction waste management plan, quantifying material diversion goals. Recycle and/or salvage at least 50 percent/75 percent of construction, demolition and packaging debris. Calculation may be done by weight or volume, but must be consistent throughout.
  • MR 4.1/4.2 NC/CI – Recycled Content, 10 Percent (for 4.1) / 20 Percent (for 4.2) [Post-Consumer + 1/2 Pre-Consumer] = 1 Point
    • Intent: Increase demand for building products that incorporate recycled content materials, therefore reducing impacts resulting from extraction and processing of virgin materials.
    • Requirements: Use materials, including furniture and furnishings, with recycled content such that the sum of post-consumer recycled content plus one-half of the post-industrial content constitutes at least 10 percent of the total value of the materials in the project. The value of the recycled content portion of a material or furnishing shall be determined by dividing the weight of recycled content in the item by the total weight of all material in the item, then multiplying the resulting percentage by the total cost of the item.
  • MR 5.1 NC/CI – Regional Materials, 20 Percent Manufactured Regionally = 1 Point
    • Intent: Increase demand for building materials and products that are extracted and manufactured within the region, thereby supporting the regional economy and reducing the environmental impacts resulting from transportation.
    • Requirements: Use a minimum of 20 percent of the combined value of construction and Division 12 (Furniture) materials and products that are manufactured regionally within a radius of 500 miles. Manufacturing refers to the final assembly of components into the building product that is furnished and installed by the tradesmen. For example, if the hardware comes from Dallas, the lumber from Vancouver, and the joist is assembled in Kent, WA, then the location of the final assembly is measured from Kent.
  • MR 5.2 NC/CI – Regional Materials, 10 Percent Extracted and Manufactured Regionally = 1 Point
    • Requirements: In addition to the requirements of MR 5.1, use a minimum of 10 percent of the combined value of construction and Division 12 (Furniture) materials and products extracted, harvested or recovered, as well as manufactured, within 500 miles of the project.
  • MR 6 NC/CI – Rapidly Renewable Materials = 1 Point
    • Intent: Reduce the use and depletion of finite ramaterials and long-cycle renewable materials by replacing them with rapidly renewable materials.
    • Requirements: Use rapidly renewable construction and Division 12 (Furniture and Furnishings) materials and products—made from plants that are typically harvested within a 10-year or shorter cycle—for 5 percent of the total value of all materials and products used in the project.
  • IEQ 4.1 NC/CI – Lo-Emitting Materials, Adhesives and Sealants = 1 Point
    • Intent: Reduce the quantity of indoor air contaminants that are odorous, potentially irritating and/or harmful to the comfort and well-being of installers and occupants.
    • Requirements: Materials used in the building interior, (i.e., inside of the exterior moisture barrier) must not exceed the following requirements:
    • Adhesives, Sealants and Sealant Primers: South Coast Air Quality Management District (SCAQMD) Rule No. 1168 requirements in effect on January 1, 2003 and rule amendment dated October 3, 2003.
    • Aerosol Adhesives: Green Seal Standard GC-36 requirements in effect on October 19, 2000.
After years of research, however, a method for breaking down and reusing rubbers floors has finally been developed, adding to the material's already extensive LEED advantages (see sidebar on page 71). And a growing market is eagerly embracing these old flooring materials.

WHAT IS RUBBERNatural rubber is an elastic hydrocarbon polymer, or elastomer. It is derived from latex found in the sap of some plants, where it helps defend them against small insects. Latex also coagulates when exposed to air.

Most latex is harvested from plantation-grown pará rubber trees (Hevea brasiliensis) when they are five to six years old. Rubber trees must be "tapped" every seven to nine years, or they will stop producing latex. The trees are not destroyed or harmed in the process. Natural latex rubber is used in products such as latex gloves and balloons. Rubber trees will not grow in North America, so most of our rubber products are made from synthetic rubber.

The most widely used synthetic rubber copolymer is made from styrene and butadiene. Styrene-butadiene rubber (SBR) was developed in Germany prior to World War II, but became prevalent in the United States during the war as a replacement for natural rubber supplies no longer available from the Far East. Vulcanized SBR offers superior abrasion resistance and aging stability in the presence of certain additives.

To create more durable products, the molecular structure of SBR is set through vulcanization—the application of heat, pressure and steam. Vulcanized rubber is less sticky and therefore easier to work with in manufacturing than rarubber, and can be engineered for specific mechanical properties for products such as hoses and shoe soles. Hard vulcanized rubber, known as ebonite, has higher styrene content and is used to make bowling balls and the mouthpieces for woodwind instruments like saxophones and clarinets.

Rubber flooring is commonly manufactured by vulcanizing SBR. Vulcanized rubber flooring provides superior durability without losing resiliency when compared with other polymeric/elastomeric flooring technologies.

Because of its molecular structure, vulcanized rubber flooring cannot be melted down to mold a neproduct, which adds significant challenges to recycling compared to other manmade hydrocarbon flooring materials. Some manufacturers will chip down old materials and reintroduce binders to create neflooring products; but until recently that was the only option—and demand was limited by the resulting "speckled" designs.

CRACKING THE RECYCLING CODERubber flooring offers one of the lowest life-cycle costs along with a reduced environmental impact. In recent years, recycled vulcanized SBR has been increasingly popular in municipal landscaping mulches, playground surfacing, rubber crumb (or "sand") for athletic fields, and in other applications such as pavers and edgings. Much of this material was made from tires. Rubber flooring had been left on the sidelines because of the complications adhesives introduced to the grinding and chopping process … until now.

An innovative new chopping and shredding method has been engineered that allows rubber flooring to be processed into mulch, soft "stone," and rubber crumbs for use in landscaping, athletic fields and playground applications.

Designers and contractors accustomed to the job site recycling programs instituted by the carpeting industry have been waiting for other product categories to come up to speed. Thanks to an innovative partnership between the supplier and the recycler, some rubber flooring manufacturers can now offer the same cost, logistical and environmental advantages.

Here's hothe rubber flooring recycling program works:

  • Collection:
    1. Product must be removed from the existing installation and prepared for return shipment.
    2. No scraping of the adhesive from the backside is needed.
    3. Product should be stacked on a pallet as neatly as possible or collected in a Gaylord (large cardboard) container. Containers and pallets are provided by the manufacturer in the program.
  • Shipping preparation:
    1. Be sure to shrink wrap, strap or band the skid or container securely for shipping.
    2. Product should be kept dry prior to shipping.
    3. The skid must be free of other construction or demolition debris.
  • Return of product:
    1. Contact the recycling company to arrange for the pickup of the product.
    2. Secure the freight payment method in advance.
    3. Include the project name, location and contact information so the program operator can provide you with a letter stating the amount of product diverted from landfills for your records.

Rubber flooring samples can also be returned to suppliers' vendor partners for reuse in other products. Program suppliers may, on request, test samples of a floor being removed to ensure it can be recycled.

Once at the recycler, the old flooring is prepared, chopped and shredded. If desired, a special EPA-approved adherent paint can be applied in a range of colors to the chopped rubber to give it uniformity, although consumers tend to prefer a mix of the flooring's original colors. Incoming material can be sorted by color before being recycled for specific color combinations.

The machinery used by the recycler is custom engineered to operate more efficiently—and less expensively—than other rubber flooring chopping and shredding equipment on the market. Special blades had to be developed because, surprisingly, rubber dulls tooling five times faster than grinding concrete. Depending on the durometer or hardness of the rubber, friction in the process can raise temperatures to 300 degrees within five minutes.

In the year since the industry's first rubber flooring recycling program began, more than 1,000 tons of material—both removed flooring and factory scrap—have been diverted from landfills.

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A NEW AFTERLIFE FOR RUBBER FLOORSRubber flooring that has been converted to playground mulch creates a safer play area, and keeps thousands of tons of rubber out of landfills. It conforms to U.S. Consumer Product Safety Commission guidelines, and has earned ADA approval.

As landscaping mulch, recycled rubber flooring is considered a safe compound and is harmless to plants. It also lasts much longer than organic mulch materials. Compared to landscaping rock, chopped rubber delivers much more volume with less than half the weight, making it less expensive to haul (and requiring less labor to disperse).

Recycled rubber's role in athletic fields is to aerate artificial turf. That sand-like substance you see bouncing up around football players as they run? That's rubber recycled into a crumb form. Athletic shoemakers have even developed special shoe designs and sole compounds for maximum performance on artificial turf with rubber crumb.

Recycled rubber flooring is being combined with rebinders to make pavers and even Olympic weights. Larger rubber "stones" are also being used in concrete blocks, rather than real stones, to give them better slip-resistant properties.

The ability to recycle and reuse rubber floors is a major leap forward for designers and contractors. Now, many of the same properties that make SBR rubber a great commercial floor will benefit consumers, children, athletes and the environment, well into the future.

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