ABOUT FIXTURES AND INTERIOR FINISHES
Because green building puts such a heavy influence on a tight building envelope, indoor air quality is directly affected by building materials and finishes used inside. Controlling air leaks, installing high efficiency windows and doors and using thick layers of insulation all contribute to energy efficiency and comfort. But these steps also can trap pollutants inside where they can contribute to a variety of health problems, especially among children. Choosing materials that do not contain dangerous pollutants is essential for a green-built house.
Interior finishes also provide an excellent opportunity to practice resource conservation. Materials such as stone and wood are prized for their natural beauty as well as durability. Paying attention to where these materials come from and how they are harvested or mined, refined and transported is the best way of making the best decisions for a sustainably built house.
Choose flooring that is durable and safe
The best choice for flooring is a material that will last a long time, and that can be a tall order in high-traffic areas or places that get wet. Materials with low durability, such as cheap carpeting or thin vinyl, must be replaced more frequently, contributing to higher maintenance costs, an unnecessary use of new resources and more strain on local landfills. Ideally, flooring also will not lower indoor air quality by off-gassing chemical contaminants.
A wood floor should last nearly as long as the house, even though it is likely to accumulate dings, dents and scratches from hard use. Wood can be sanded and refinished a number of times, and it can be reused in another house if it is pulled up before the end of its service life (just look at the number of companies that sell reclaimed or salvaged wood products). Excluding the finish, wood is a completely natural and biodegradable material that won’t adversely affect indoor air quality.
But there are potential drawbacks with wood. It will need periodic maintenance, and when used in wet areas like a bathroom or kitchen wood has the potential to degrade or discolor.
The key is to choose wood that comes from a sustainable source
Although expensive, wood flooring milled from salvaged timbers or logs reclaimed from lake and river bottoms represents excellent green recycling. Reused flooring may be even better. At the other end of the spectrum are wood species that are harvested without regard for the impact on sensitive forest environments or their native peoples. One way of choosing appropriately is to specify wood listed by a certifying organization, such as the Forest Stewardship Council. FSC-certified wood is available from a growing number of suppliers. In rural areas, it may be possible to mill wood taken from the building site into flooring, or to buy from local sources known to harvest trees responsibly.
This type of flooring is a manmade counterpart to solid wood and has the same inherent advantages in conserving resources as I-joists do when compared with solid framing material.
While technically a grass, bamboo looks like wood. It’s made by cutting bamboo stalks into thin strips, gluing the strips into planks and then milling the edges with a tongue-and-groove profile. It is typically available as either a vertical grain or flat sawn plank.
From a green standpoint, bamboo flooring has a number of advantages:
* Bamboo regenerates rapidly.
* Flooring is more dimensionally stable than solid wood and can safely be installed over radiant-floor heat.
* Bamboo flooring is as dent-resistant as some hardwood species.
* Pre-finished varieties can be walked on immediately and because the finish is already cured it will not off-gas volatile organic compounds.
The caveat is to buy bamboo flooring from a source known to provide high-quality material. The finish on lesser grades may not be especially durable and the bamboo itself may not be as hard as advertised.
Another type of engineered flooring consists of a relatively thin layer of wood glued to a manmade core, such as particleboard. Like bamboo, engineered flooring is dimensionally stable and it makes good use of high-quality face wood. The drawback is that the particleboard or wood composite core may be manufactured with a binder containing urea formaldehyde, a pernicious indoor air pollutant. Look for flooring manufactured with an alternative binder. Also keep in mind that engineered flooring can’t be refinished as many times as solid wood.
Watch out for carpeting
Because carpeting can be relatively inexpensive and plush under foot, it’s an attractive flooring option for many homeowners. But from a green point of view, there are some real drawbacks:
* In damp conditions, carpeting can harbor mold that’s difficult if not impossible to remove.
* Carpeting can collect dirt, pet dander and, more alarmingly, contaminations such as herbicides, fertilizer and pesticides tracked in from outdoors.
* Volatile organic compounds in carpeting and the adhesives used to manufacture it can off-gas inside, lowering indoor air quality.
* Low-quality carpeting doesn’t last very long, increasing maintenance costs for the homeowner. Worn out carpeting is likely to end up in a landfill.
In a household with young children who spend a lot of time crawling around on the floor, the laundry list of unpleasant or unhealthful substances that collect in carpeting should be a serious concern. Frequent vacuuming will collect some of it, but some compounds may soak into carpet fibers and amount of a permanent problem.
The Carpet and Rug Institute, however, has found a way to address concerns over chemical contaminants. Its Green Label and Green Label Plus programs require independent lab tests for a number of chemicals, including vinyl acetate, toluene, benzene and formaldehyde. If carpeting is the choice for finishing flooring, make sure it carries the Green Label Plus certification that ensures low amounts of these compounds will be emitted.
* Consider a natural fiber, such as sisal. For wool carpeting, check that it does not contain foreign-sourced wool that has been treated with an insecticide, a requirement under U.S. Department of Agriculture rules for wool from New Zealand and Iceland.
* Shop around for environmentally friendly carpet companies, such as InterfaceFLOR, which recycles used carpeting. Its carpet tiles can be replaced individually if they become damaged.
Concrete makes a superb finish floor
One of the big advantages of using concrete as the finish floor is simple resource conservation. In slab construction, this eliminates an entire layer of flooring, and the savings can be significant.
* Concrete can take a variety of finishes and color tints, applied after the concrete has been placed or added to the mix before it is poured.
* With high thermal mass, concrete is ideal in passive solar designs and for radiant-floor heat.
* Concrete is extremely durable and it should outlive many other types of flooring with little or no maintenance.
* Unlike carpeting, concrete won’t gather pet dander and other contaminants so it makes a net contribution to indoor air quality.
Using concrete over a crawlspace or basement is more problematic. At roughly 150 lb. per cubic foot, concrete probably will require beefed up floor framing. If floor framing sags or bounces, cracking can be a problem.
Concrete also carries with it some green concerns, especially the amount of energy that it takes to produce portland cement, its key ingredient. One way of minimizing this problem is to specify concrete that contains fly ash, a byproduct of coal-fired power plants. Millions of tons of fly ash are produced annually in the U.S., and diverting more of it to concrete production is a great way of relieving pressure on local landfills. What’s more, fly ash concrete is stronger than mixes containing all portland cement, and it’s easier to pump and less likely to crack. It requires less water than portland cement, so it’s easier to use in cold weather.
1. A skilled installer is essential. Look for one with experience on placing and finishing interior surfaces.
2. Make sure the architect or engineer who designs the framing knows the finish surface will be concrete so the extra weight can be taken into account.
3. Some hairline cracking is a real possibility so homeowners expecting a flawless surface will be disappointed.
4. Concrete is by nature a porous material that will absorb stains if it’s not sealed (and maintained).
Tile and stone are highly durable
When properly installed, these venerable building materials should last hundreds of years and wear into a delightfully mellow surface requiring very little care.
Like other hard surfaces, tile and stone are not especially porous so they won’t trap contaminants. That contributes to high indoor air quality. Among other green benefits:
* High salvage potential. Providing it is not damaged during removal, tile, and especially stone, can be reused in new installations.
* Recycled content is available. Some manufacturers use recycled content in manufacturing new floor tile. For example, Crossville says its EcoCycle Tile contains 40% recycled ceramic content. TerraGreen makes tiles with high recycled-glass content.
* Affordability. Although some tile and stone can be pricey, there are many low-cost options that make this type of flooring very economical.
From a design standpoint, few materials offer as much diversity as tile. It’s manufactured in many colors, textures and sizes. A skilled installer can use tile to make small rooms look bigger, lighten a dark space or disguise uneven and out-of-square floors in old buildings.
For avid green builders, one consideration is the distance that tile and stone have to travel to get to the building site. Because it’s heavy, tile can consume a lot of energy in transportation so sourcing locally made tile is better than ordering it from Italy, at least from a green standpoint.
1. Weight. While ceramic tile isn’t very heavy, thick pieces of bluestone or slate set in a mortar bed can strain floor framing designed for standard loads.
2. Flexibility. Neither stone nor tile is very tolerant of bouncy floors, which can crack the tile, the grout or both. When installed over a wood subfloor, a special membrane may be needed to isolate tile from seasonal movement in the subfloor.
3. Adhesive. When tile is set in a premixed adhesive, look for a brand with low VOCs.
Bird’s Eye View
The many materials that make up the finished interior of a house play both practical and decorative roles. Floors and countertops are wear surfaces where durability is a key consideration. Walls, ceilings and trim are more cosmetic but they offer a variety of green opportunities in resource conservation and maintaining indoor air quality. When chosen carefully, fixtures and appliances can make an important contribution to energy conservation.
Floors and Walls
Cabinets and Counters
Paints, stains, and oils finishes