Interior Finishes
basic choices for green building 
hardwood flooring from certified forests is becoming more available for interior applications
Products for interior environments should be carefully chosen for reasons of durability and indoor air quality, and for sustainable attributes such as their source, embodied energy, and recycled content.
Flooring and Floor Coverings
Flooring and floor coverings are subject to abuse from feet and heavy objects, and to the collection of dirt, moisture and other contaminants. A good flooring material should be very durable to reduce the frequency of replacement, and easy to clean. At the same time, softer surfaces may be preferred for reasons of comfort, noise reduction and style, setting up a potential conflict in choices. Raw materials and the effects of manufacturing should also be considered.
Carpet systems including carpet pads and adhesives have been identified by the US Environmental Protection Agency as potential sources of indoor air pollution. The Green Label and more stringent Green Label Plus of the Carpet and Rug Institute help prevent the most severe instances of toxic off gassing from new carpet.
High end commercial carpets tend to be more chemically stable than inexpensive residential quality carpets. Some manufacturers are willing to provide detailed air quality testing data on their products. Carpets may also contribute to air quality problems by trapping pollutants and moisture that can also lead to the growth of mould, mildew and dust mites.
Flexible foam carpet padding frequently contains brominated flame retardants [BFRs]. These compounds which are chemically similar to PCBs are raising health concerns because they are being found in human blood and breast milk world wide, and there is evidence of health effects. BFRs can be released in to the living space especially as the carpet ages.
In residences, hard surfaces with area rugs that can be thoroughly cleaned are often preferable to wall-to-wall carpeting. Modular carpet tiles that can be replaced selectively reduce the cost and environmental impact of re-carpeting an entire room when one area becomes worn or damaged. Some carpet tiles also contain a high percentage of recycled content and others can be resurfaced and reused. Carpet tiles with random patterns allow easy replacement of individual tiles.
Some companies now have extensive recycling programs. When installing new carpeting, it may be possible to have the old carpeting hauled away for recycling at a price no higher than the cost of disposal.
A wide variety of high quality carpet is now made from recycled pop bottles [PET] and offers the feel and performance of conventional carpeting in residential and other low traffic settings. Natural fibre carpet with jute backing is a good alternative to synthetic fibres, particularly if the carpeting is made domestically. Imported wool carpet is typically treated with pesticide before it can enter the country.
The underlayment used between the sub floor and the floor covering is often made from Lauan, a tropical hardwood that comes from unsustainable logging operations in southeast Asia. Other underlayment products are available and should be chosen in consultation with your floor covering supplier.
For example, a recycled content, gypsum based, formaldehyde-free underlayment is available and is recommended by major tile manufacturers as a substrate. Under carpet, a recycled newsprint and paraffin product is a good alternative. Wood underlayment is also available.
Vinyl flooring, whose primary component is polyvinyl chloride [PVC] may be a source of VOC off gassing, both from the flooring itself and from the adhesive. There is also a concern about toxic by-products such as dioxins, which may be produced if the material is incinerated at the end of its useful life.
Natural linoleum made primarily from natural cork and linseed oil is a possible substitute, though it is currently manufactured only in Europe. VOCs are also released from linoleum, but these are from minimally processed linseed oil and are not considered as harmful as those from petrochemical sources.
Ceramic and porcelain tile have a high embodied energy, but their durability makes them environmentally sound in the long run. Some high quality ceramic tile incorporates recycled glass from automobile windshields. Regionally produced stone tile, is a good natural finish when sealed with low toxic sealers.
Terrazzo is a long lasting, non-toxic floor covering option that uses crushed stone and sometimes post consumer recycled glass, in a cementitious matrix. The embodied energy of Portland cement is a consideration.
Epoxy-based synthetic terrazzo may also use recycled glass; while the 100% solids product is considered safer for installers, and is benigh when cured, bispehonahonal-A [BPA] is used in the manufacture of the epoxy. BPA is a bio-accumulating chemical considered by some experts to be an endocrine disruptor, even at minute quantities. Like bromibated flame retardants, BPA has been showing up in nature in increasing amounts.
Hardwood flooring from certified, well managed forests is a good environmental choice. Other hardwoods come from forestry operations that may or may not be environmentally responsible. Tropical hardwoods, in particular, should be avoided unless FSC certified, due to the sensitivity of those ecosystems.
North American wood products can be certified under a few third-party certification systems. [See the January/February, 2007 issue of SABMag.] Wood flooring milled from salvaged timbers, or from submerged logs is another option.
Fast growing bamboo is manufactured into hardwood like strip flooring by a number of Southeast Asian companies, offering an intriguing alternative to traditional hardwood flooring.
[Editor's Note: The vast majority of bamboo flooring used in North America comes from lowland China where the land has been used for agricultural purposes for centuries. Although there is no current certification system in place for bamboo forests or plantations, this may come as the export market grows. Bamboo regenerates after cutting, and selective harvesting (as opposed to clear cutting) which have proven to generate the highest long term yield, thus encouraging sustainable management practices.
Interior Finishes and Trim
Particleboard and medium-density fibreboard [MDF] are almost always made with a urea formaldehyde [UF] binder. This is one of the largest in-home sources of formaldehyde gas - a known human carcinogen. These products can offgas for five years or more into the living space. UF-based particleboard and MDF are typically used for cabinet boxes, substrates for countertops, shelving, and stair treads. If possible, these materials should be avoided. Any UF-based materials used in a building should be sealed with a low-toxic, low-permeability coating.
[Editor's Note: This industry is making strides to reduce UF emissions through the Composite Panel Association's Environmentally Preferable Product [EPP] Certification Program. Some companies are making formaldehyde-free wood panels through use of alternate resins. See the January/ February, 2007 issue of SABMag.]
Conventional drywall is quite attractive from an environmental standpoint. It is typically made from 100% recycled paper backing and natural gypsum, which is plentiful and can be low-impact to extract. More and more drywall today contains pre-consumer waste in the form of synthetic gypsum created by sulfur removal systems in the smokestacks of coal-burning power plants. This material is sometimes referred to as flue-gas desulfurization gypsum.
The joint compound used to finish drywall contains synthetic additives that may affect some chemically sensitive people; specialty alternatives are available. Dry-mix, setting-type joint compounds, which are sold in powder form and mixed on site, contain fewer additives.
Cabinets made from nontoxic materials and finishes or solid wood are available. People with chemical sensitivities often find enameled-metal cabinets to be the least problematic.
Clear wood trim materials are more expensive, but have a high aesthetic quality. Finger-jointed trim for painted applications, and veneer-covered, finger-jointed trim for stain applications, are good substitutes.
Paints and Coatings
As paints and coatings dry the carrier evaporates, leaving the active agents in place. For most products this carrier was traditionally a volatile organic solvent that turned into an airborne volatile organic compound (VOC) as it evaporated. Air quality regulations and health concerns have driven a shift toward waterborne products. Evaporating water isn’t a health concern, though other components of the coating or adhesive still generally release some VOCs.
Paints and coatings have their greatest effect on indoor air quality during and immediately after installation. The health hazard is particularly acute for painters. Most conventional products offgas VOCs, formaldehyde, and other chemicals that are added to enhance the performance or extend shelf-life of the product. Little scientific data is available on the health effects of many of these chemicals-and even less on the effects of exposure to a combination of such chemicals that may occur in buildings. Quality substitutions, which are lower in toxicity or nontoxic, are available for all of these products.
Even so-called zero-VOC materials may still release small amounts of organic compounds. People with chemical sensitivities should always test these products before applying them on their projects, or having them applied by painters. Alternatives to conventional paints made from plant-based solvents may also release significant amounts of VOCs, but many people find these compounds less objectionable than those derived from petrochemicals.
Aside from solvents with well-known health effects (such as benzene, toluene, or xylene), the scientific community offers little guidance on the distinction between acceptable and problematic VOCs.
In certain categories, the GreenSpec criteria for “low-VOC” products is 50 grams per litre, which is well below even the most stringent VOC regulations in California.
While wet-applied products emit the most VOCs immediately after curing, some continue to offgas such compounds for a long time. In addition, VOCs emitted during curing can become attached to other surfaces in the space, especially fabrics, and then be re-emitted over time. To reduce this problem, painting should be done with soft surfaces covered and direct ventilation provided until the coating is dry.
For wood-floor finishes, waterborne polyurethane is suggested. It contains no crosslinking agent-a type of chemical that adds hardness but is toxic. Waterborne finishes have been tested for durability, and they wear comparably to solvent-based ones. Installers often prefer waterborne finishing products because they dry quickly, allowing several coats to be applied in one day.
