Posted by: jeb1 | December 6, 2010

Wall to Wall

With a focus on durability and growing attention toward recycled materials, gypsum wallboard offers a range of opportunities to make greener selections.

By: Katy Tomasulo

Historically, most building pros likely haven’t given their drywall selections much thought. But with new wallboard products that target mold and moisture, extend durability, enhance noise suppression, and contain increasing amounts of recycled materials, builders and remodelers are paying closer attention. The sustainable-building movement also is shifting that commodity perception, as green building teams look to earn points toward green project certification.

Indeed, gypsum offers a number of opportunities to go green—from recycled content to local manufacturing credits to long-term durability. More than ever, options abound for product specifiers to make sustainable choices that meet the needs of each area of the home.

RAW MATERIALS

For decades, most North American manufacturers have used recycled-paper facing on their panels and some incorporate leftover end product back into the production stream; more recently, the introduction of synthetic gypsum has upped the category’s reuse opportunity even further.

Unlike traditional gypsum, which is mined from quarries, synthetic products use waste material from coal-fired power plants. The two materials arrive in different states—natural is a rock, synthetic comes in wet form—but the chemical makeup is the same. “Synthetic is indistinguishable in terms of the look, the feel, and the performance,” says Mundise Mortimer, technical manager for National Gypsum.

According to the Gypsum Association, synthetic has grown to nearly 30% of gypsum sales. Most manufacturers offer both types, so be sure to specify synthetic and ask for documentation when ordering if you plan to seek green standard points for recycled content. Also note that synthetic drywall is easier to obtain in the East; the high recycled content isn’t very green if you’re shipping it all the way across the country.

The EPA recently proposed new regulations on the disposal of coal combustion residuals (CCR); however, the agency says, products in which the CCRs are encapsulated or used as an ingredient in manufacture, such as wallboard, raise minimal health or environmental concerns and, at this time, do not need to be regulated.

Many manufacturing facilities are now built next to or near the source, so gypsum materials may also qualify for regional credits. But, says Glenn Miller, architect specialist at Temple-Inland, some supply may come from Canada or Mexico, so ask about the origins of the raw materials as well as the manufacturing facility.

Though not required to earn green standard points, two manufacturers—USG and Temple-Inland—have obtained Scientific Certification Systems (SCS) approval verifying the percentage of recycled content in some of their products.

DURABILITY

“The essence of sustainability is durability, longevity, and performance,” says Barry Reid, sustainability manager at Georgia-Pacific Gypsum. “If you have to replace it, it’s not sustainable.”

One of the factors driving the evolution of gypsum over the past decade was the influx of mold lawsuits. Though the crisis wasn’t caused by drywall—blame construction practices, particularly faulty window installations and poor ventilation—it was the walls that got moldy as a result of water infiltration.

The first step, naturally, is to manage the moisture so that it doesn’t enter the wall system in the first place. As a backup, manufacturers developed wallboard featuring moisture-resistant cores combined with treated paper facings or integrated fiberglass mat surfaces.

Though a novelty at first, more builders are starting to catch on to the idea, says CertainTeed’s Amy Lee. “It saves callbacks and problems down the road,” the marketing communications manager says of the company’s M2Tech drywall.

Most of these specialty panels carry a premium, but can be substituted for traditional products in areas where moisture and humidity may become a problem, including bathrooms (except behind the tub and shower surround), above kitchen sinks, in laundry rooms, and in finished basements.

Other keys for durability, says Lee, are to keep the materials dry during installation and to verify compatibility of materials and compounds.

In addition to improving product life span, preventing mold and mildew growth also helps promote optimal indoor air quality, the industry says. And while traditional wallboard is considered a low-emitting material, several manufacturers have obtained product verification for IAQ from Greenguard or third-party laboratories like MAS to reassure buyers, particularly as polymers and other features have been added for moisture resistance and sound attenuation.

A NEW STANDARD

Unlike some building product categories, gypsum wallboard doesn’t have an over-arching product certification program or even a single-attribute label that all manufacturers strive for; as previously indicated, some firms have chosen to undergo indoor air quality or material reuse testing, but those labels aren’t widespread enough to fully aid selection. UL Environment recognized this need and slotted wallboard to become one of its first green product standards.

Released in mid-October, the technical standard for ULE100, UL’s Sustainable Standard for Gypsum Wallboard, provides a multi-attribute label for wallboard that evaluates a number of product traits—including recycled content and indoor air quality—as well as elements of the manufacturing process and a manufacturer’s social responsibility.

The consensus-based standard is currently undergoing ANSI approval.

RECYCLING AND REUSE

Like many areas of the built environment, the first step to keeping gypsum out of landfills is to create as little waste as possible through proper planning and design. Still, some scraps and leftovers are inevitable, so consideration must be given to recycling and other disposal methods.

Recycling options vary from market to market. There is no national reuse stream, but some manufacturers will work with select builders and drywall contractors to take back unused product to be reused in manufacturing. Enhanced products, such as those with non-paper facers, may be harder to recycle than traditional boards.

Local waste recyclers are another option. The Gypsum Association recommends checking the National Institute of Building Sciences’ searchable Construction Waste Management Database at http://www.wbdg.org.

Finally, some builders opt to grind up the material on site for soil amendment.

NOISE CONTROL

A lesser-known component of sustainable building, sound attenuation for applications such as shared walls, media rooms, and under second-floor laundry rooms can lead to a more comfortable home consumers will want to live in longer.

Like moisture resistance, sound control starts with smart building practices, says Chris Pinckney, product manager at National Gypsum. For example, start with 24-inch-o.c. installation and then a product like the company’s SoundBreakXP. Ensure joints are backed by framing members, limit penetrations, and caulk the wall perimeter, he says.

For a system approach, GreenGlue offers a noise-proofing viscoelastic compound, noise-proofing clips, sealant to fill gaps between floors and walls, and joist tape.

OTHER OPTIONS

Following the recent developments of mold- and moisture-resistant boards, manufacturers have continued to experiment with wallboard to move its purpose beyond simply a surface.

Taking IAQ an additional step forward, CertainTeed recently introduced AirRenew, a product the company claims absorbs formaldehyde emitted from other interior products, encapsulates it, and renders it inert.

At Greenbuild last year, National Gypsum unveiled ThermalCore, which has a Micronal PCM paraffin wax in its core that acts as a thermal mass to absorb heat when it isn’t needed and release it when temperatures drop below 73 degrees F. The product, appropriate for climates with high daily temperature swings, is still in testing and may be available next year.

With developments such as these, a continual focus on durability, and increasing attention being paid to sustainable attributes, gypsum has moved quickly from commodity afterthought to high-performance material.

Katy Tomasulo is Deputy Editor for EcoHome.

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