And, manufacturers like to point out, engineered wood, while a composite of different kinds of wood fibers, still starts as trees, which are renewable and remove carbon dioxide from the atmosphere.

Some manufacturers are taking the additional step of incorporating wood from sustainably managed forests that are certified by programs such as the Forest Stewardship Council, the Sustainable Forestry Initiative, the Canadian Standards Association, and the American Tree Farm System. Manufacturers of engineered wood can earn certifications at different levels if they buy a substantial portion of their wood from sustainable forests and keep tabs on the chain of custody of the product.

Lingering Challenges

"I'm not sure why anyone would choose not to use [engineered lumber]," says green home builder Jon Alexander of Seattle-based Sunshine Construction. Aside from their environmental qualities, he adds, "I like their pretty darn consistent quality. When you order one of them, you know what you're getting."

Still, the product, which APA-The Engineered Wood Association predicts will increase significantly in production and use over the next five years, costs more than solid-sawn lumber in most markets, leaving some builders ambivalent about pitching it to potential buyers.

"I would prefer to use all engineered wood if I could, but that's not the case," says Lance Hobson, owner of Legend Builders in Paco, Wash., which builds 24 homes a year—mostly on spec—and uses engineered I-joists in all of them.

For custom homes, however, he offers the buyer the option of paying the 6 percent to 8 percent more he estimates a home would cost if he used engineered wood exclusively, and he has only had two takers, who were focused on building green homes.

Engineered wood is a hard sell, he says, because "without going into the negatives [of solid-sawn wood], there's no way to tell the positives. If I told them that [traditional] wood would warp, crack, and split, I'd be casting a doubt over the workmanship of the homes I built with wood."

At Winchester Homes in New Market, Md., sales staff tell potential buyers about the benefits of engineered wood, but the builders decide where to use it. "If they want a big, open space, engineered wood is what we're going to go with," says Randy Melvin, the builder's director of research, standards and design assurance. "If they want a less-squeaky floor and the flatness of the floor is important, we use engineered wood."

Tim Mosely, brand manager for Canfor, notes that most buyers don't know what kind of wood builders use in their homes. "The benefit is really more to the builder than the actual home buyer," he says.

Mosely notes that the green benefits are growing as manufacturers develop sophisticated software that helps builders order and cut precise lengths. Software from Boise Cascade, iLevel by Weyerhaeuser, and others allow builders to accurately specify the amount and types of materials needed, so builders buy less, avoid overbuilding, and waste less.

"Wood is a green building product, engineered wood is extremely green, and Boise's design process makes the whole thing even greener," says Boise spokesman Dale Robley, who notes that the industry is gravitating toward electronic designs that limit the need for paper for drawing them or gas for delivering them.

"You go to a typical jobsite and you see these piles of waste every night," Robley says. "There's absolutely no excuse for that anymore." -- BUILDING PRODUCTS

Most structural engineered wood is glued together with binders that contain phenol formaldehyde, a product with minimal off-gassing.

The binders used for some non-structural, interior-grade products, like particleboard, MDF, and hardwood plywood, however, can contain urea formaldehyde, a volatile compound that is classified as a carcinogen. Urea formaldehyde is also linked to respiratory problems, eye and nose irritation, and allergic reactions. The telltale sign of its presence: the sweet smell that most new kitchen and bathroom cabinets emit.

New regulations in California will restrict urea formaldehyde emissions, but do not deal with phenol formaldehyde. In response, manufacturers are developing formaldehyde-free binders, using products like polyurethane and even soy. Last summer, the California Air Resources Board adopted new caps on the amount of urea formaldehyde used to bind wood products used indoors, to take effect in 2009.

Resources


American Tree Farm System: www.treefarmsystem.org
APA-The Engineered Wood Association: www.apawood.org
Canadian Standards Association: www.csa.ca
Forest Certification Resource Center: www.certifiedwood.org
Forest Stewardship Council: www.fscus.org
Sustainable Forestry Initiative: www.sfiprogram.org

Ainsworth Engineered. Because it is engineered to accept flexural loads, 0.8E Durastrand Rimboard oriented strand lumber can be used for most short-span headers up to 9 feet, the maker says, eliminating the need for the builder to install a separate component. The 1-1/4-inch-thick rimboard comes in depths up to 24 inches and lengths up to 24 feet. The rimboard is manufactured from CSA-certified forests; many of the company's other products are manufactured from SFI-, FSC-, and CSA-certified forests. 877-661-3200. www.ainsworthengineered.com.

Georgia-Pacific. The XJ 85 I-joist has pre-cut holes for builders to install plumbing, HVAC, and electrical systems. This lightweight joist is available in a 16-inch depth with standard lengths ranging from 6 to 26 feet. SFI-certified, this manufacturer recovers 4 million tons of paper and paperboard for use in its facilities, and uses wood waste to fuel some of the building products and paper plants, according to the company. 800-284-5347. www.gp.com.

Roseburg Forest Products. A code-accepted alternative to solid-sawn lumber for conventional framing, RigidLam LVL studs are straight, strong, and stiff, allowing for faster installation and straight walls, says the firm. The studs are approved for use in one-hour fire-rated wall construction. Sixteen-, 18-, 20-, 24-, and 48-foot lengths are available. Wood for the company's LVL products comes from second- and third-generation trees from well-managed timberlands; a number of the company's other products contain wood from FSC-certified timberlands. 800-347-7260. www.roseburg.com.

iLevel by Weyerhaeuser. Builders can use the company's iLevel line of TimberStrand laminated strand lumber for beams, wall studs, rafters, treated sill plates, columns, window and door headers, and concrete form board. The material is manufactured using a process in which small strands of wood are carefully dried, positioned, and bound together with resin to form high-strength structural framing members, the company says. The manufacturer uses several kinds of trees to make its engineered lumber, including aspen, poplar, and maple, and more than 85 percent of the company's solid wood products are SFI- or CSA-certified. 800-242-4854. www.ilevel.com.

Universal Forest Products. Open Joist is an open-web, all-wood floor truss that uses less wood fiber than solid-sawn joists, the company says. This engineered floor truss takes advantage of the triangle's structural power and the forces of compression and tension to create strong support, according to the manufacturer. The company gets 85 percent of its wood from vendors that comply with FSC, SFI, and CSA standards and uses 25,000 tons of recycled wood dust per year in the production of composite decking and railing, the company says. 800-598-9663. www.ufpi.com.

Canfor. This company's engineered finger-joined lumber is made from kiln-dried spruce pine fir. Designed for use in framing houses, the maker uses melamine formaldehyde so the lumber will withstand weather conditions during construction. About 96 percent of the manufacturer's forest harvest is CSA-certified, and the company seeks to eliminate waste by creating boards in varying lengths up to 36 feet and by using younger, fast-growing trees and wood scraps. 360-647-2434. www.canfor.com.

Boise. These I-joists are made from Versa-Lam laminated veneer lumber. All of the grain is parallel to the length of the wood, with knots and other imperfections dispersed in the manufacturing process, according to the company. Most of the company's wood comes from SFI-certified forests and when installed, this manufacturer's engineered wood products use 50 percent less wood than ordinary lumber, the manufacturer says. Some dealers can precision end-trim to length based on exact dimensions, eliminating waste. This manufacturer also offers its Plans Room software to home builders, who can post home plans for all project members to view. 800-232-0788. www.bc.com/ewp.

Louisiana Pacific. SolidStart laminated strand lumber is available in lengths up to 64 feet. Made from thin, longer-length wood strands that are oriented parallel to the product's length, builders can use this lumber for headers and beams, wall studs, roof beams and rafters, truss chords, rimboard, and stair stringers, according to the manufacturer. SolidStart laminated strand lumber is SFI-certified, and more than 80 percent of the log is used in the final product. The remaining 20 percent of the log is used as fuel for the production process, the company says. 888-820-0325. www.lpcorp.com.