Flooring may seem like a minor factor in sustainable building, but considering its large surface area and the high amount of traffic it receives, choosing the right type is quite important. In terms of environmental and health impacts, its main points of distinction are material extraction/production and indoor air quality effects.
Before any flooring materials were invented, the ground itself served as the floor in buildings – perhaps covered with straw, waste products, or furs. Some cultures used animal blood to harden their dirt floors or mint to deodorize them. Sand floors, by contrast, could be swept out and replaced when they became dirty. The first materials that could be considered flooring as it is currently thought of were stone and tile. After that, everything from concrete, wood, rag rugs, elaborate mosaics, and Persian carpets to rubber, vinyl, and cork were used on floors.
The best floor will reduce a building’s environmental impact and toxicity level, and function well for building occupants.
Types and Trade-Offs
There exists a wider selection of flooring materials today than ever before. The most common include wood, bamboo, tile, vinyl, linoleum, and carpeting. When it comes to building green, not all of these materials are equal. For instance, vinyl flooring, like other PVC products, is made of petroleum, is not recyclable, and tends to off-gas harmful chemicals. Most carpeting is currently made from nylon, another petroleum-based product. Neither vinyl nor nylon is biodegradable. Stone flooring is durable but nonrenewable and requires a large amount of energy for extraction, transport, and installation. In other cases, the material itself may be renewable, such as bamboo or cork, but the products used to finish the floor may contain volatile organic compounds (VOCs), a health hazard.
Despite the trade-offs presented by every flooring type, there are some general guidelines that can help designers, owners, and builders make more sustainable choices. For instance, no matter what type of floor is chosen, always avoid sealants and adhesives with VOCs. See if flooring made from recycled (especially post-consumer) materials could be appropriate or get creative and use salvaged materials. Green Label Plus, Greenguard, FloorScore, and Cradle to Cradle product certifications are helpful in finding both flooring materials and cleaning/maintenance products that are environment- and health-friendly.
Carpeting has come a long way in terms of sustainability and its softness and noise-dampening properties make it a popular choice. Look for carpeting and carpet padding made either from recycled materials or natural fibers such as wool or seagrass rather than nylon, and be sure it does not contain brominated flame retardants or other harmful chemicals. Since carpeting is one of the less durable flooring types, consider carpet tiles, which can be replaced individually in damaged or high-traffic areas. Carpeting collects dirt, dust, and other allergens, so avoid it when occupants have sensitivities. Finally, make sure the chosen carpet is recyclable in your region, or ask the manufacturer if they have a buy-back program in which they recycle or reuse the materials. Billions of pounds of carpeting are landfilled each year, so recycling is crucial.
Hardwood flooring is a beautiful, biodegradable option that can be cleaned much more thoroughly than carpeting. Make sure to purchase wood that is formaldehyde-free and that has been certified by the Forest Stewardship Council (FSC), ensuring that its source is sustainably managed. Bamboo and cork are rapidly renewable alternatives to hardwood and can also be FSC-certified. Bamboo is harder than hardwood, while cork is softer but just as durable as wood. One drawback of these, especially of bamboo, is the decreased likelihood of finding materials regionally. In any case, avoid cork-vinyl composites and bamboo flooring with glues containing VOCs.
Linoleum is a biodegradable material made from cork dust, limestone, linseed oil, and other ingredients. True linoleum (as opposed to vinyl, which is sometimes generically called linoleum) is only manufactured in Europe, which does increase its transportation footprint. Linoleum is durable, colorfast, available in a wide variety of patterns, and has some antimicrobial properties. It may have a faint smell.
Stone and ceramic or glass tile are highly durable and can often be reused or recycled. Keep in mind that stone is a finite resource and try to source all of these materials locally, as their weight requires more energy for their transport. Terrazzo is made of crushed stone or glass bits held together with cement or another binding agent. It offers a good way to use recycled flooring material, but avoid varieties that use epoxy binders (made with Bisphenol-A, an endocrine disruptor).
Rubber flooring is appropriate for some specific applications such as exercise areas. It is non-slip, durable, easy to clean, and doesn’t need adhesives. It tends to off-gas odorous compounds, but these are not particularly toxic. Natural rubber should be avoided by those with latex allergies.
Owners looking for an inexpensive and very low-impact flooring option may want to consider the rather unconventional earthen floor. Materials needed for earthen floors—a clay, sand, and straw mixture, plus an oil or wax sealant—can be obtained for as little as a $1/ft2! One methods for laying an earthen floor can be found here.
How to Choose
When choosing flooring, first consider the function of each room or area. Then ask: How much traffic is this area expected to have? What is the likelihood that the floor here will be exposed to moisture? Will this room need flooring that can help dampen noise levels? Might any of the occupants of this room have allergies, chemical sensitivities, or asthma? What are likely ways this area will become dirty and how much time and money will be devoted to cleaning and maintaining this floor? Consideration of these various factors helps narrow down flooring options and ensures that the flooring in each area is well-suited to its purpose. Of course, various owners will prioritize these factors differently, but this list is a good place to start. The best floor will reduce a building’s environmental impact and toxicity level, and function well for building occupants.
- Buyer’s Guide to Green Floor Materials
- Navigating the Flooring Thicket: Find the Greenest Way to Meet Your Needs