Wednesday, April 15, 2009

Eco Friendly Lumber

                                                                    



Building for a healthy planet



Strong and beautiful, wood is the material of choice for all kinds of home projects, from building a crib to finishing a basement to constructing a whole house. What's more, wood is a renewable resource. But even though a tree can be replanted to replace one that gets cut down, wood consumption does have consequences. Here's how to use this marvelous material in ways that help maintain lush forests, abundant wildlife, and healthy people.



Top Tips


At home

  • Waste not, want not. Try not to buy more wood than you need, and remember the first rule of carpentry: "Measure twice, cut once." When you have leftover wood, keep it in a scrap pile that's protected from the elements and use it for other projects, or donate it to someone who can use it.


When shopping, look for

  • The FSC label. When buying lumber and wood products, look for products with the Forest Stewardship Council (FSC) label. That's how you know the wood came from forestry operations that meet strong environmental, social, and economic performance standards. A few major home improvement chains now carry FSC lumber and other wood products.
  • Eco-Friendly Lumber

  • Strong wood from small trees. High quality beams, boards, panels, and trim can be crafted from flakes, chips, and strips of wood that are pressed and glued together. Some well-known forms of this wood, like particle board, are not high-quality products and can't be used for structural purposes. But most engineered wood is stronger than solid wood, as well as lighter and straighter. And it comes from fast-growing, small-diameter trees, reducing the demand for the older, larger trees that are so important to healthy forests.

  • Healthy adhesives. It's important to know about the adhesives used in engineered wood products like plywood, particle board, and its stronger cousin, medium-density fiberboard (MDF). Some are much safer than others. The most common adhesive is urea formaldehyde, a chemical that can be emitted from these products for years after they're made. What's wrong that? For a start, it's carcinogenic. It can also cause allergic reactions and irritate respiratory systems. Some panel manufacturers have switched to less toxic polyurethane or soy-based adhesives, although these products can be harder to find and may cost more. If you can't find a panel that's specifically labeled as having no added urea formaldehyde, consider exterior-grade plywood. It's made with phenol formaldehyde, which emits less than urea formaldehyde. Or use oriented strand board (OSB), which is usually made with a polyurethane adhesive.

  • Wood from wastes. A few companies make sheet-panel products (similar to particle board and MDF) out of straw or recycled newsprint instead of wood. Straw is an agricultural waste--what's left over after rice, wheat, rye, and other grasses are harvested.

  • Salvaged wood. Or you can use salvaged wood from factories, houses, and other structures. It's often high quality--especially well-aged beams and boards fashioned long ago from huge, old trees--but can require a lot more preparation than new lumber. If you are thinking of using salvaged wood for structural purposes, check with your building department first. Local building codes may not allow you to use it for building roofs or load-bearing walls.




Other Considerations



  • "Structurally insulated panels" (SIPs) are a relative newcomer to the home building scene, but they're catching on fast because they dramatically speed up construction time and improve the home's energy efficiency. A SIP consists of a thick layer of rigid foam insulation sandwiched between two sheets of "oriented strand board" (OSB), which is made from strands of wood arranged in crisscrossing layers and bound with an adhesive. Using SIPs can greatly reduce the time it takes to build a conventional wood-framed home. They lock together tightly, providing excellent insulation and reducing air infiltration.

  • If you're building a major addition or a brand new home, you'll save a lot of wood by using advanced framing techniques (also called "optimum value engineering," or OVE). These practices make it possible to use 15% to 30% less wood without sacrificing strength or durability. Common techniques include framing corners with two studs instead of three and framing walls with 2 x 6 inch studs spaced 24 inches apart instead of the more conventional 2 x 4 inch studs spaced 16 inches apart.




Benefits...


...to you
SIPs speed up construction time and lower costs. Advanced framing techniques can reduce lumber costs by 15% to 30%.

...to your health
Engineered wood products made without added urea formaldehyde keep your home healthier.

...to the Earth
Using less wood and choosing wisely among the salvaged, engineered, and FSC-certified options reduces pressure to harvest forests, which store carbon dioxide and provide critical habitat for wildlife.



Common Mistakes


Buying painted wood. Think twice before buying salvaged wood covered with paint, which may contain lead. You can test for lead-based paint with inexpensive swabs available at hardware stores.

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