Environmentally Friendly Decks
Live a little . . . outside!
Decks allow us to do more of our living outdoors, so it’s no surprise they’re one of the most popular features of today’s homes. They can be a great investment. But it takes smart planning to make your deck as environmentally friendly as possible, whether you’re building it yourself or hiring a contractor.
- Repair so you replace less. If you have an old deck, you may be able to repair the worn places and avoid using more trees and preservatives. Boards that have started to decay from infestation or water damage should be removed right away. Otherwise, wood-destroying organisms will spread.
- Apply a safe preservative. To maximize the lifespan of your deck, apply a penetrating preservative every other year. Fortunately, you probably will no longer be able to find chromated copper arsenate, a preservative that contains arsenic, which can cause cancer and other illnesses. The EPA banned most residential uses of chromated copper arsenate at the end of 2003. Instead, find a preservative considered safe by the EPA such as “quat.”
- Seek the sun. If you are dreaming of a new deck, find a sunny place to put it, if possible. A warm location not only guarantees that you can enjoy it longer each year, but you won’t be as tempted to use outside heaters when the weather gets chilly.
When shopping, consider
- No deck at all. Because decks can be costly to construct and maintain, you should first consider whether a patio of stones, concrete, or tile might be a better choice.
- The codes. Bad construction invites decay and infestation by termites and other wood-devouring pests. Saving a few dollars by cutting corners today can mean big expenses tomorrow.
- Mr. or Ms. Greenjeans. If you are hiring a builder, find a LEED-certified one. These contractors use their knowledge of green building techniques to make projects more environmentally sound.
- Wood certified by the Forest Stewardship Council. Looking for the FSC label is the best way to find wood that has been logged sustainably and with care for the environment.
- Treat your ends well. The sawed ends of wood boards are particularly vulnerable to decay. So put the ends in a bucket with preservative and let them soak it up for a few minutes.
- Snazzy fasteners. Instead of driving screws or nails through the surface of the deck into the joints, consider using one of the various types of fasteners that attach from below or through the sides of the boards. They may cost more, but they are less likely to make a path for water to get into the wood and cause decay. Because no nail or screw heads show, they also make a better-looking deck.
- Hardware that curbs corrosion. Use corrosion-resistant nails, screws, and connectors when building with treated wood.
- Flashy metal. When a deck is attached to a house, the joists (the parallel beams underneath the floor) are tied to a “ledger,” a large board bolted to the side of the house. This ledger should have a flashing that goes under the siding and over the ledger. Without it, water can seep in between the ledger and the house and cause the wood to rot.
There are three basic kinds of material used for decking. Since each has its pros and cons from a green point of view, you should consider which best fits your lifestyle.
- Will you have lots of plants that you’ll be watering? Do you live in the rainy Northwest? Would you rather be hiking than staining on weekends? A water-resistant synthetic lumber might be your wisest choice. A number of brands now on the market are made of wood waste and recycled plastic. Some are 100% recycled plastic. This lumber can’t be used for joists because it bends too easily. But it works well for railings and the floor itself. Synthetic lumber never needs treatment or painting, doesn’t release toxic substances, and keeps old, treated lumber from filling up landfills. While it costs more upfront than treated lumber, it will be cheaper in the end, because it lasts so long. As to esthetics, synthetic lumber is gray. But keep in mind that even the most beautiful and well-maintained redwood decking also grays with age.
- Are esthetics and using wood–but not chemically treated wood–important to you? Consider weather- and water-resistant premium wood such as redwood or cedar or even teak, a tropical wood. Although these are more expensive than treated wood, they resist rot and will hold up for a long time. However, for better looks and a longer life they need periodic applications of a preservative. If you go this route, make sure your wood is FSC-certified.
- Do you love real wood, but can’t afford the premium prices? Chemically treated softwoods might fill the bill. This type of lumber lasts a long time, and the treatment enables builders to use lower-cost, abundant woods like fir or pine that look beautiful, but would quickly rot or be infested with termites and other vermin if not treated. If you have a child or a pet that might gnaw on the wood slats, however, you might want to stay away from treated wood.
Decks help city dwellers get outside, especially kids who grow up dining and playing on them.
…to your wallet
Decks are expensive. Including installation, synthetic lumber and premium woods can cost $20 a square foot or more, with softwoods running in the $10 to $16 range. But the average deck returns 75% of that outlay when you resell your house, and 90% if you live in a climate with mild year-round weather.
…to the Earth
Despite the higher cash outlay upfront, synthetic wood can spare forests and save you from using chemical preservatives. (Steer clear of vinyl, however. It produces hazardous pollution during manufacturing and disposal.) If you choose wood, FSC certification ensures that the forests that provided your decking were harvested in an environmentally sensitive way.
- Touching the ground. Wood should never be in contact with the soil, even if treated. Use concrete pillars instead, or you’ll make an open invitation to destructive fungi and insects.
- Forgetting about your health. If you have to cut any chemically treated wood, you’ll need a respirator mask. Keep a drop cloth under it to collect the sawdust.
- Being careless with treated lumber. Shower after working with it, and wash your work clothes separately. When you dispose of any treated lumber, make sure it goes to a lined landfill, and don’t burn it. Burning it will release toxic substances into the air. (Call your local waste authority if you need to know more about disposal.)
- Jumping the gun. Don’t tear down an old deck just because it was treated with copper arsenate. You might rub off more toxic stuff than if you leave it alone. Instead, coat it with oil- or water-based penetrating stains every other year. This reduces the ability of the arsenic compound to come off. Use a pigmented stain; it will be more effective than a clear one because it blocks ultraviolet light, which can speed release of the harmful compounds.
- To find certified wood dealers near you, check this guide prepared by the Rainforest Alliance.
- If you have trouble finding a LEED-certified, or environmentally aware contractor, check with the Green Building Institute.
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