Long valued for its strength and longevity, stone is a beautiful natural resource. But with stone countertops, floor tiles, sink basins and even walls surging in popularity, it’s important to consider just how eco-friendly this natural material really is.
Recent technology makes acquiring stone less stressful on the earth and more readily available across the nation. In the past, only a few places in the country could fabricate certain types of stone, which meant raw stone was shipped from the quarry to a fabricator, then shipped again to retailers. Today, most stone is locally fabricated, which means raw stone is sent directly to retail locations, where it is cut and sold to local consumers. Because shipping stone requires so much energy, make sure any stone you buy is fabricated locally.
“There is now technology available on the local level to fabricate hard stone,” says Chuck Muehlbauer, technical director for the Marble Institute of America. “Years ago, if you wanted granite countertops, there were only a few places in the country that could do it.”
Unlike carpet or synthetics, stone doesn’t collect allergens or offgas volatile organic compounds (VOCs), and it requires no harsh cleansers. Though most stone products for residential applications require a sealant, you can choose water-based, nontoxic options.
Rock is certainly natural, but are granite countertops and limestone tub surrounds as green as they seem? Before choosing stone, factor the environmental costs and the potential assets. If you make careful choices, you can have eco-friendly stone that will last for decades.
Measure the environmental cost
Stone is almost always quarried, meaning it’s cut in large slabs from the earth. Although quarrying usually produces less waste rock than metal mining does, the process permanently alters the landscape and changes the ecosystem. Quarried areas can negatively affect rain runoff, soil composition and slope, possibly even causing landslides, toppled trees or flooding. Dust from quarrying pollutes surrounding water, soil and air, and the population nearby may have to deal with noise pollution.
Quarry workers can be exposed to hazards such as poor air quality, especially in countries where labor standards are inadequate. To reduce dust inhalation, fabricators—and homeowners cutting stone tiles—need to wear appropriate safety gear, including goggles, hearing protection and a dust mask.
Heavy stone is energy-intensive to transport. Very little stone is quarried in the United States; finding locally quarried stone near you greatly improves its environmental profile. But in general, transporting rock from the quarry to your home requires vast amounts of energy. Although travertine, for example, may be a luxurious choice, the environmental (as well as the pocketbook) price is often high.
Weigh the eco-assets
Stone has no odor and doesn’t offgas VOCs, although sealants or adhesives are often necessary during installation. Request that your contractor use low-VOC adhesives and sealants or use an application that requires neither, such as setting floor tiles in Portland cement. Unlike wood or drywall, most stone surfaces won’t need refinishing; dusting, sealing or simply cleaning is all that is needed.
Well-placed stone can help lower energy costs. Dark-colored stone works well with under-floor radiant heat or passive solar applications because it absorbs and releases heat slowly. Conversely, a light-colored stone surface in a shaded area is naturally cool to the touch, making it ideal for hot climates.
Stone’s long lifecycle is one of its greatest selling points. Unlike less hardy materials, stone is not going to end up in the landfill after a few years’ use. “It will be there until the house is demolished or the owner gets tired of it,” Muehlbauer says.
Tip the scales
Salvaged or reclaimed stone is quite eco-friendly. Because it eliminates further quarrying, using salvaged stone in your home drastically reduces its embodied energy.
Brent Kroh, vice president of sales at Elmwood Reclaimed Timber in Kansas City, Missouri, sells reclaimed limestone and granite blocks from old buildings, and says the selection will vary by region. Antique stone may have beautiful, mellowed colors; interesting fossils; or best of all, a fascinating history. The price is usually just a bit more than new stone, Kroh says.
To find salvaged stone, check with a reclaimed lumber specialist or an architectural salvage shop. Fabricators may also offer reclaimed options. Design studios in major metropolitan areas sometimes carry stone from demolished historical buildings—but authenticity may be difficult or impossible to verify.
Recycle your rocks
If you have stone in your home that is cracked, stained or otherwise permanently damaged, you can usually reuse it. Consider converting it into smaller countertops, tiles, windowsills or a fireplace hearth. If you can’t reuse it, check with a local construction exchange such as Habitat ReStore or stone fabricators for recycling information. Otherwise, use stone scraps in landscaping; it can be crushed or used as decorative slabs.
Maintence tips for stone surfaces
One of stone’s key ecological benefits is its durability—you won’t be replacing this material every few years. Make sure yours gives a full life of service by following these easy care tips.
■ Seal porous stone or stone in heavy-use areas with a food-safe or nontoxic sealer.
■ Protect surfaces from scratches and stains by using felt pads under appliances or décor, a towel or coasters under unglazed china and trivets under hot dishes.
■ Never use abrasive scrubbers and liquids or powdered scouring agents.
■ Blot spills immediately with a damp towel.
■ Clean with warm water and a stone soap or a few drops of mild liquid dishwashing detergent—too much may leave a residue. Rinse, then dry with a soft cloth.
■ Avoid commercial all-purpose cleansers and those that are acidic, such as lemon and vinegar.
Health concerns about granite countertops have surfaced recently. Homeowners across the United States are reporting that testing has found high levels of radon (a radioactive gas linked with lung cancer) in their granite countertops. Experts are quick to point out that not all varieties are dangerous, but as granite’s popularity has increased, more varieties from more countries (that emit varying levels of radon) have become available.
If you’re worried about your countertops, it’s a good idea to have a radon test conducted in your home. The Environmental Protection Agency recommends removing countertops if the test reveals a level of more than 4 picoCuries per liter (pCi/L) of air. The American Association of Radon Scientists and Technologists has a list of certified inspectors. Learn more, including information about a radon test you can conduct yourself, by visiting the EPA.
Woodstock Soapstone Company
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M. Teixeira Soapstone
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Green Mountain Soapstone Corporation
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To find a local stone fabricator:
Marble Institute of America
Click on “Consumer Resources”
National Kitchen and Bath Association (NKBA)