Your choice of flooring material will affect everyone in your home for decades and have substantial impacts on the environment at large. Floors usually account for more surface area than anything else in a house except the walls, so they have an outsized effect on indoor air quality. Adults, children and pets will walk on them, play on them, sit on them, wear them down and breathe anything they emit for many years.
Since flooring may take up thousands of square feet, large quantities of raw materials, glues, finishes, adhesives and cleaners—with all their associated environmental impacts and energy requirements—are required to make, move, install and maintain it. But you can select flooring materials that will help you maximize the quality of your indoor environment while minimizing damage to the natural environment.
Eight Green Flooring ChoicesBambooThe world’s largest grass, bamboo grows quickly in a wide variety of soils and, depending on the species, can be harvested in a three- to five-year cycle. Bamboo flooring is generally made by slicing bamboo into strips, boiling it in water, laminating it into board, and kiln-drying the resulting material.
Most bamboo flooring comes from the Asia Pacific region, particularly China and Vietnam, which means energy requirements and air emissions for transporting bamboo flooring to North America are significant.
Adhesives used in bamboo flooring sometimes contain a urea formaldehyde resin, although products that contain minimal or no formaldehyde are available.
Installation is by nailing, stapling or gluing; tongue-and-groove flooring sections can minimize the need for fasteners or adhesives. Ask the installer to conduct as much sawing and sanding as possible outside the home to minimize air quality impacts.
Bamboo flooring is hard (harder than many hardwoods, in fact) and will last for 30 to 50 years. Once removed it will biodegrade in landfills or can be burned for energy.
StoneStone is nonrenewable. Sought-after stone types—granite, marble, sandstone, slate, limestone and others—may need to be transported long distances. However, stone’s durability amortizes these costs over a long period of time.
Stone is only minimally processed, but quarrying, cutting, polishing and handling this heavy, hard material requires a great deal of energy. Stone quarrying can also affect the surrounding landscape and water tables, and stone saws can throw irritating dust into the air.
Installation typically requires specialized knowledge and stone-cutting and -grinding tools. Ask the installer to conduct as much cutting and grinding as possible outside the home to minimize air quality impacts.
Stone has no emissions profile beyond potential radon emission. Query suppliers to ensure that radon is not a concern with a particular stone type. Select a low-VOC sealer to finish stone flooring, or select stone flooring that does not require sealing.
Stone flooring must periodically be resealed against stains—as often as every year for high-traffic areas. Sealer will evaporate eventually even from unused areas. Beyond this, simply vacuuming it is enough to maintain its appearance.
Some stone types—particularly marble, sandstone, limestone and slate—are relatively soft and can scratch and absorb stains easily. Granite is harder and more scratch and stain resistant.
Stone flooring can last decades or even centuries, long enough that disposal is a minor issue. Stone can be disposed of safely in bulk, or crushed and reused as aggregate for other building materials, like composite stone tile.
CorkCork has a slight smell that most people consider pleasant. It is highly renewable, although at a lower rate than bamboo. Even “virgin” cork is harvested sustainably from several Mediterranean countries. The bark of cork trees can be removed once every 7 to 10 years without harming the tree or its habitat, a process that has been used throughout recorded history. However, energy requirements to transport cork from the Mediterranean are significant.
Some manufacturers claim their cork flooring is hypo-allergenic, but in any case, all-natural cork flooring is preferred over cork-vinyl composites that have a PVC backing. In the past, urea formaldehyde was used to bind cork granules into flooring, but it was phased out in the 1980s. Today, urea melamine, phenol formaldehyde and natural proteins are used as binders instead, greatly reducing VOC problems.
Techniques for installing cork planks or tiles vary from nailing to gluing; take care to choose low-VOC adhesives. Tiles will need to be sealed; a natural wax or low-VOC polyurethane sealer is recommended.
Cork floor keeps its shape well and is naturally mold, moisture and rot resistant. It’s as durable as hardwood flooring, biodegradable and non-toxic (it can even be ground up for compost).
Ceramic and Glass TileCeramic and glass tile have been used as flooring materials for thousands of years. Some recycled-content tile is made from light bulbs, ground glass and auto windshields. Although energy requirements for producing ceramic tile are high, it is durable and produced in many locations from abundant natural clays. Choose tile from a local source to reduce energy used in transporting this heavy material.
Ceramic tile set in cement may be the most acceptable floor in terms of indoor air quality. It’s also more durable than tile set using adhesives. Tiles come either glazed (sealed with a smooth finish; highly moisture and stain resistant) or unglazed (somewhat coarser and more porous). Tile glazes are inert since they are baked onto the tiles at high temperatures, but as usual, adhesives should be chosen with care.
Ceramic tile requires some specialized tools and knowledge to cut and install; however, it can be laid with simple Portland cement-based grout, which does not emit vapors and requires very little maintenance. Ask the installer to avoid cutting and grinding tiles inside your home as much as possible.
Ceramic tile will outlast vinyl flooring if properly installed, and it biodegrades after removal. Tiles can be reused and may also be crushed and recycled as aggregate material for sidewalks, roads—even bathrooms.
WoodWood flooring is warm, and recycled woods in particular add warmth to a space because of their years of weathering. Virgin hardwood flooring must be harvested from trees with long growth cycles: red and white oak, maple, and occasionally ash or birch. North American beech is depleted and should be avoided. Growth cycles for softwood flooring, such as pine, are somewhat shorter than for their hardwood cousins. Clear-cutting and overharvesting are concerns, so take care to purchase flooring that is FSC-certified or otherwise sustainably harvested.
“The obvious ones [to avoid] are hardwoods that are rare and endangered, which is what most people put in their homes,” Mangan says. “Brazil cherrywood is popular, and that’s not sustainable.”
That said, any wood may be sustainably raised and harvested. U.K.-based Friends of the Earth rates woods on their endangered status in cases where no FSC alternative is available.
Increasingly, building suppliers carry salvaged wood, which amortizes the energy cost of growing and harvesting wood (though energy is required to disassemble the source building). Wood’s long replacement cycle also distributes its environmental impacts over decades.
Laminate flooring combines several layers of materials (typically a laminate, an “image layer,” a core and a backing) to create an aesthetically pleasing, highly durable surface. Note that while laminate flooring may contain sawdust, wood chips and other re-used wood residues, it may also contain formaldehyde, a known toxin. Look for a FloorScore seal on laminate flooring or check its VOC emissions against one of the other emissions standards in the “Use” section above.
Hardwood floors are excellent for indoor air quality, but take care in selecting a finish. It’s best to buy wood flooring prefinished at the factory, where off-gassing can be handled in a controlled environment.
Wood floors require sealing; try to choose adhesives and sealers that give off few or no VOCs. Wood itself off-gasses only minimally and does not harbor dust mites or mold. Properly finished floors retain only minimal dirt.
LinoleumLinoleum is experiencing a big comeback as an alternative to vinyl tile. In addition to being more environmentally friendly, linoleum also has practical advantages over vinyl: patterns are dyed all the way through to the backing, ensuring even wear; vinyl tiles have a pattern superimposed on them and show wear more dramatically.
Linoleum is a mixture of linseed oil (from flax plants), pine rosin, wood flour, cork flour, limestone and pigments, which form into granules and are pressed together onto a jute backing. All natural linoleum is manufactured in Europe, adding to energy costs for transporting it to North America. (Make sure you look for “natural linoleum,” as “linoleum” is sometimes used to refer generically to vinyl flooring.)
In use since the mid-1800s, linoleum’s chemistry is well-understood, although some have raised concerns about aldehydes off-gassing from linoleum’s constituent linseed oil. Linoleum’s faint smell may not be to everyone’s taste. However, linseed oil is a natural antimicrobial agent, making linoleum a good choice for kitchens.
Linoleum is not recommended for areas where moisture may seep through the underfloor, such as concrete basements; however, its edges can be heat-welded, eliminating seams. Dry cleaning is considered more effective than wet cleaning, so linoleum flooring reduces waste water.
RubberRubber is generally used for play, outdoor and other areas where non-slip surfaces are needed, such as kitchens. Virgin rubber is manufactured from latex, the sap of rubber trees, which typically grow in tropical areas. Asia provides most of the world’s natural rubber; rubber can also be produced synthetically.
Several varieties of rubber flooring are made from recycled materials, typically rubber tires, meaning that there are abundant raw materials in North America. Conversion to rubber flooring requires energy but transport costs are generally lower than for imports. Recycled rubber flooring is generally less expensive and more durable than virgin flooring.
Rubber’s properties and effects are well understood after more than a century of industrial, commercial and residential use. It is chemically stable, although it does off-gas slightly, giving it a distinctive smell, but emission of toxics is low. Because of its natural tackiness and form-fitting qualities, it can be installed without adhesives, further lessening off-gassing compared with other materials. It is easy to clean, provides good support and is highly durable.
Rubber flooring usually is flammable and some people are allergic to it; although hypo-allergenic products are available, you may be better off using it only outdoors if you have sensitivities.
Carpets & RugsStart examining a carpet by looking for the new Carpet and Rug Institute seal of approval, called Green Label Plus. For this certification, the CRI has adopted California’s 01350 standard, which is the most rigorous and tests for emissions of individual VOCs rather than just the overall level of VOCs.
Synthetic carpeting is commonly criticized for its petroleum-based fibers and the off-gassing of VOCs in the home. Recycled carpeting is made primarily from post-consumer plastic soft-drink containers, while recycled carpet padding can be made from old carpet padding and reclaimed carpet fibers. Amazingly, about 30 percent of all foam cushion used for carpet padding in the United States comes from imported waste fibers. Natural carpets and rugs can be made from wool, cotton or even grasses with minimal processing and treatment.
Binders still used to make synthetic carpets and padding may outgas for years after installation, with varying levels of emissions and toxicity.
Wall-to-wall carpets of all kinds require either an adhesive or the use of stretching and carpet tacks. Because of off-gassing concerns, ask the installer to unroll and air out the carpet in a well-ventilated area before installation, and to use only low-emitting adhesives. Ventilate the installation area as well as possible for 48 to 72 hours afterward.
Once installed, carpeting has excellent sound- and thermal-insulating properties. The problem, Mangan says, is that it can’t be kept truly clean.
“Carpet not only is typically made from petroleum products and doesn’t break down ever, but it never gets clean; it just collects dirt and dust and stuff,” he says. “It’s always going to contain whatever’s fallen into it.”
While carpet is the softest flooring material considered here, it is also requires relatively frequent replacement (about every 11 years). Just 4 percent of carpet is recycled, a figure the CRI says will increase to 20 to 25 percent by 2012.
Paul Kretkowski wrote this article, with contributions from consultants Marian Keeler and Kirsten Ritchie, and architect Andrew Mangan for GreenHomeGuide.
