Some products help us use other products or materials more efficiently. For example, drywall clips allow the elimination of corner studs, engineered stair stringers reduce lumber waste, and concrete pigments and polishing systems can turn concrete slabs into attractive finished floors. We also recognize some products, like vacuum plumbing systems, which use less material than their conventional counterparts. Many products with this attribute are fairly unique, so we bring a skeptical eye to manufacturer claims, but not a specific standard.
Background noise, whether from indoor or outdoor sources, adds to stress and discomfort, and poor acoustical design inside can exacerbate problems from background noise and reverberation of sounds. Products that absorb sound and prevent sound transmission can be considered green, although there are so many such products available that we also look for especially innovative products, as well as products with additional green attributes such as recycled content and strong energy performance. We also look for sound-masking systems with exceptional performance characteristics.
QuietRock™ sound-control drywall for walls and ceilings is made with a ceramic-polymer-gypsum composite that has near-zero VOC emissions. It provides impressive sound transmission reduction, installs quickly, and results in very little increase in wall thickness, compared with other sound-control options. Metal is integrated into their shear-rated and THX™-certified panels. QuietRock is available in thicknesses ranging from 1/2" to 1-3/8".
Gypsum board, or drywall, is typically made with 100% recycled, unbleached paper facings that are bonded without adhesives onto a gypsum core.
Mined gypsum is still widely used in gypsum board production, but recycled and synthetic gypsum increasingly contribute to production. Post-consumer recycled gypsum is mainly comprised of scraps from construction. Pre-consumer recycled content includes synthetic, or flue-gas desulfurization (FGD) gypsum, a coal-combustion byproduct obtained from stack scrubbers that remove sulfur from coal-fired power plant emissions.
Synthetic gypsum may replace up to 100% of the natural gypsum in drywall. The amount of recycled content in drywall varies not only by manufacturer, but also by product and by manufacturing location, so if you’re looking for recycled content, be sure to ask manufacturers for specific figures.
In synthetic gypsum, and to some degree in virgin gypsum as well, toxic hazards and heavy metals are concerns at the manufacturing and end-of-life stages of the product. Although heavy metals don’t concentrate in synthetic gypsum the same way they do in fly ash, they are still present in small amounts, and those amounts may increase as power-plant emissions standards tighten. (For more discussion of these issues, see "Measuring Drywall Against Environmental Standards” in EBN.)
While indoor environmental quality concerns haven’t yet emerged with gypsum board made in the U.S., watch out for leaching concerns in landfills, and when recycling gypsum board as an agricultural amendment.
Paper facings provide an ideal medium for mold growth in conditions of high humidity, or if wallboard gets wet due to flooding or leaking water. To combat this, manufacturers include biocide treatments in some product lines, and offer other product lines with integral cellulose or fiberglass fibers instead of paper facing.
GreenSpec is concerned about introducing biocides into building products, and considers them ineffective in fighting mold. GreenSpec recommends non-paper-faced wallboard in applications where moisture may be a concern, and includes specific listings for those products.
GreenSpec also lists standard drywall products for North American manufacturers that typically offer recycled content, Greenguard Children & Schools certifications, and certification to UL Environment ISR 100.
Drywall is energy-intensive to produce, and so avoiding waste is one of the easiest steps to reduce your environmental impact in this area. For example, consider 54"-wide gypsum board for more efficient wall coverage in rooms with 9' ceilings.
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