New Jersey deck builder Gustavio del la Cruz says his Millston Township remodeling company is “in the direction of being green,” but that it’s hard to nail down which decking products are eco-friendly. “Every manufacturer says their product is green,” says de la Cruz, who owns Barrett Contracting. And he admits, “We’d like to use green practices on all of our projects, but only 20% are.”
The reason: Few of his consumers ask for eco-friendly decks—and those who do can’t figure out if wood, wood-plastic composites, or all-plastic deck boards are greenest. With no green standards in the deck-building industry, many remodelers likely don’t know, either.
Indeed, decking manufacturers themselves are still figuring it out. Manufacturers of products ranging from uncertified but chemical-free exotic hardwoods to all-virgin, recyclable PVC deck boards claim their products are as eco-friendly as plantation-grown, pressure-treated wood or recycled-content, hard-to-dispose-of composites.
Here is a review of the green claims and qualities of the most common decking materials.
The oldest and most popular decking material is also the one that is renewable: wood.
Western cedar and redwood are homeowner favorites because of their rich color and natural resistance to rot and insects. Decks made from FSC- or SFI-certified wood are universally accepted as green because suppliers can prove through chain-of-custody that their wood comes from sustainably managed forests.
Still, there’s plenty of redwood and cedar on the market that comes from poorly managed forests whose owners indulge in unsustainable harvesting. Plus, some builders say wood from young redwood trees does not have the natural resistance of old growth. “There’s an illusion on the part of the consumer that if they get a redwood deck, it’s not going to rot,” notes David Johnston, author of Green From the Ground Up and president of What’s Working, a Boulder, Colo., consulting firm. “That’s not true.”
Likewise, he says, new cedar trees, while less afflicted by fungus and insects than the white sapwood of young redwoods, can be less stable and more apt to warp and twist than older trees, so deck boards need replacing more often.
A growing number of homeowners and pros have turned to exotic hardwoods, especially Brazilian-grown ipe. Among the tallest in the Amazon region, these huge trees can grow trunks measuring up to 6 feet in diameter. The consumer appeal of this unusually strong, dense wood and similar exotic species is a stunning reddish-brown hue that weathers to a silvery patina, coupled with a natural resistance to rot, decay, insects, mold, and even fire without the use of chemicals.
But for builders committed to using certified lumber, ipe and other South and Central American hardwoods are hard to come by, and the price is often inflated by demand and the high cost of earning certification in South America. The energy expended in transport is another detractor.
So the most commonly used—and least-expensive—wood deck boards are made from fast-growing Southern pine, grown domestically on plantations where sustainability isn’t an issue.
What becomes an issue is its need for treatment with a preservative to ward off rot and termites. Preservative manufacturers voluntarily bumped chromated copper arsenate (CCA) from use in the early 2000s; since then, alternative treatments, like ACQ (alkaline copper quat), have become commonplace. The replacements weren’t perfect, however, as early formulations of ACQ leached more copper into the soil than CCA and corroded steel fasteners. Newer formulations, including micronized ACQ, are said to be less likely to leach and corrode. More recently, a number of manufacturers have introduced non-metallic preservatives for deck boards.
Amid the growing number of new wood treatment products is heat-treated lumber, which forgoes chemical protection for a heat-and-steam treatment that changes the wood’s makeup so that it is no longer edible to insects. The lingering question with these relatively new materials is whether the energy required to super-heat the wood negates the environmental benefits of avoiding chemicals.
Most composite manufacturers fashion their deck boards from a combination of wood fiber and recycled plastic (including plastic bags and milk jugs), although some rely on virgin polyethylene. Most companies warranty the long-lasting decks for 25 years.
Brands initially lured wood-weary homeowners with a promise of maintenance-free decks that won’t splinter and don’t need painting. But the decks required more upkeep than advertised, and problems with mold on some brands led to class-action lawsuits against several manufacturers.
In response, some, like A.E.R.T., have added zinc borate—a mild fungicide and flame retardant—to their boards. Others, like Correct Building Products, introduced recycled-content composite boards topped with a skin of mold-resistant, virgin plastic that adds a scratch-resistant, colorfast seal and shields the organic part of the deck.
The added elements detract from the decks’ green makeup, but Martin Grohman, chairman and founder of Correct Building Products, says they are necessary in today’s marketplace. “People want this really high-performance surface with no color fade, antimicrobial performance, ease of cleaning, and low upkeep,” he says. “To deliver that kind of performance, you give up something in terms of recycling.”
Some makers of composite decks claim their products are made from 90% or more recycled materials. But the same plastic content that makes the boards durable and resistant to decay renders them difficult to dispose of because they’re slow to decompose in landfills. Plus, because the boards combine wood and plastic that cannot be separated at the end of their life, there are few ways to reuse them except to recycle them back into deck boards, although there is a barely existent system for doing so.
Grohman notes that the industry’s next step is to strengthen the recycling process. CorrectDeck, for example, stamps the underside of its products with the ingredients so recycling-minded future homeowners can get it back to the company for reuse. And the North American Deck and Railing Association is working on a standard that will help deck builders order more precise amounts of material so they have less waste to dispose of.
Like many products, composite’s green analysis is one of trade-offs: Not all of the materials are renewable or recyclable, but in exchange is a long-lasting product that doesn’t need to be recoated with chemicals.
Another response to complaints about mold, scratches, and color fading on composites is the growing number of all-plastic decks with limited lifetime warranties. Even Trex, the first to market with composite decking, offers a cellular PVC deck board, Escapes.
Some plastic decking, like Fiberon’s Sensibuilt, a solid-core, cellular PVC decking material, and Renew Plastics’ Evolve Decking, a high-density polyethylene product, include recycled content. Some others use all-virgin plastics.
Either way, these all-plastic deck boards do not mix in wood fiber, so they resist mold. And while some green builders would not call plastic decking “green,” manufacturers tout the fact that it can be recycled. “You could put [our] product in with your curbside [recycling] pickup, and it would be picked up with milk jugs and water bottles. It would go to a recycling center,” says Terry Marquart, manufacturing manager for Renew Plastics.
Plus, because plastic decking doesn’t decompose, its life span is indefinite, a quality manufacturers say qualifies it as a green product. That same characteristic, environmentalists counter, causes a problem when the material is dumped into landfills.
“[Green] used to be defined as the amount of recycled content in your product,” says Kristen Baer of Azek Deck. “But now, people are looking at sustainability, durability, long life cycle, and recyclability. That’s hard to calculate.”
Sharon O’Malley is a freelance writer in College Park, Md.