Resin in the sun: should you use composite lumber for your next deck spec? - doctor spec - deck design

Residential Architect, Jan-Feb, 2003 by Nigel F. Maynard

What could be better than a well-placed wooden deck? It's a perfect spot for entertaining outdoors, an ideal place to while away a summer afternoon. But it's not without its vices: Traditional lumber may keep your client's budget in the black, but when homeowners complain about weekends spent sanding and resealing, everyone will see red.

mixing it up

Made from wood flour and recycled or virgin plastic, composite lumber has become a hot product because it offers the benefits of wood without the maintenance issues typically associated with most species. On the market for about 10 years now, composite lumber occupies about 10 percent of the $2 billion decking market and is growing at a rate of about 15 percent to 20 percent per year, says Paul Bizzarri, marketing manager for TimberTech in Wilmington, Ohio. Manufacturers claim it's the spec of the future.

A primary reason for the growth is maintenance--or the lack thereof. While the product isn't completely maintenance free, makers say it's as close as you're going get to a hands-off product. Most composite decks need only an occasional sweeping or hose washing, and those that have been painted will require repainting after a few years.

Gail Lindsey, FAIA, who specializes in green design, favors composite decking because many products contain recycled wood and recycled plastic bags or milk jugs. Low-maintenance benefits attract her, too. "You don't have to treat it once you install it," says the principal of Design Harmony in Wake Forest, N.C.

Other architects spec the material for aesthetic reasons. Architect Reed Axelrod, AIA, uses composites in certain jobs to solve design issues. "The product is attractive because of its longevity and its ease of maintenance," says the principal of Reed Axelrod Architects in Philadelphia. "But it also can come in tongue-and-groove styles so there are virtually no seams once it is installed. This provides a nice detailed look that is more suitable than typical deck planks."

Architect E. Gary Schloh warns that architects need to pay close attention to installation. "It is important that the contractor install the product correctly," says the principal of Architecture by Schloh in Los Gatos, Calif. "They need to know how tight to screw it down. If it's too tight, it won't look good." Schloh advises against painting a composite deck because you'll end up with the maintenance situation you tried to avoid. Also, the structural support of the deck needs to be engineered carefully. "Most composites cannot span the same distances as real wood," he says, so spec the joist spacing accordingly.

exploring the options

Architects have a wide range of decking manufacturers from which to choose. Winchester, Va.-based Trex, which claims to have installed the first composite deck in the Everglades about 11 years ago, offers wood and plastic composite decking and railing products made primarily from reclaimed hardwood sawdust and reclaimed or recycled polyethylene plastic. Five stock colors are available, or, if upkeep is less of a concern, the product can be painted or stained with an oil-base coating, company representative Maureen Murray says. Staining and painting should be done five to 12 weeks after installation, she says, when the deck has faded to its final gray color.

TimberTech sells a line of products made from a combination of recycled wood and virgin plastic. The products come in a choice of tongue-and-groove planks, 2-by-6-inch planks for the traditional look of a wood deck, and deck planks measuring 5 1/2 inches wide by 1 inch thick. Stock colors are redwood, cedar, and gray.

Correct Building Products in Biddeford, Maine, says its CorrectDeck planks are stiffer, lighter, and thinner than other composite decking, so they're easier to handle and install. The gray-, cedar-, or natural-colored planks are made from 60 percent hardwood sawdust and UV-stabilized polypropylene. And Weyerhaeuser in Federal Way, Wash., manufactures ChoiceDek, a wood fiber and recycled polyethylene product that's water resistant and free of stress points, the company says.

Other manufacturers include USPL in Boca Raton, Fla.; CertainTeed in Valley Forge, Pa.; Composite Building Products International in Barrie, Ontario, which offers deck boards, railing, trim, and fencing; and Mississauga, Ontario's CPI Plastics Group, makers of thermoplastic decking, railing, and accessories.

stacking the deck

Despite all the benefits, composites have yet to take over the industry. "New home builders have not completely adopted the product," says Bizzarri. "It might be because of awareness." At the moment, only 20 percent of the composite market goes to new construction; instead, most are installed for homeowners who are on their second decks and weary of the maintenance burden of real wood. Bizzarri anticipates greater market penetration by 2005. By that time, he claims, consumer understanding of the product will increase, and more builders and contractors will be comfortable and familiar with the material.