Early composite wood plastic boards products lacked adequate structural stiffness, often resulting in sagging park benches and picnic tables. The next generation of products featured fiber reinforcement using wood, agricultural fibers, fiberglass, and other materials. The addition of fiber reinforcement markedly improved overall strength and stiffness, and rapid growth in wood and natural fiber polymer composites consumption followed (Figure 1). Recent trends in the United States suggest continued market growth for plastic and wood-plastic composite lumber (Figure 2); whether the prolonged recession will negatively impact projected 2013 consumption remains to be seen.
In addition to decking and fencing, wood and plastic composite materials are being used today in making a wide variety of products including automotive parts, pallets, playground equipment, picnic tables, park benches and chairs, landscape timbers, railroad ties, and docks. Auto interiors and decking for outdoor applications represent the largest market for wood plastic composites in both Europe and North America. Growth is most rapid, in both regions, in the decking segment. Plastic composite decking currently accounts for 10 percent of the residential decking market in North America and 6 percent in Europe. In the U.S., use of plastic composite materials for residential decking is projected to reach 23 and 32 percent of the total decking market by 2011 and 2016, respectively (Wood 2007). Solid wood remains the primar y decking material globally.
The qualities of WPC wall cladding decking, on the other hand, are largely defined at this point by manufacturer’s claims and those of various NGOs and other organizations. The EPA is quoted by Fox News as reporting that WPC products last indefinitely (Cant 2009). The EPA’s GreenScapes website , in fact, appears to wholeheartedly endorse plastic lumber over traditional materials for a wide variety of applications. But is sweeping endorsement justified? Is everything that is being said, in fact, true? A bit of investigation into WPC performance to date suggests that caution may be in order when considering such products. For instance, various sources document a number of problems that have been encountered with plastic composite decks and a recent study offers new informa