Trex officials say contractors like the material because it can be cut as easily as wood and bent into shapes that wood could never tolerate -- leading to some pretty creative sundecks. It requires no sanding, sealing or painting, and homeowners and commercial users like it because there is little or no maintenance.

"We believe we have established our brand as the premier decking material in the marketplace," says Anthony Cavanna, Trex's chief financial officer. "We have continued to be in a 'sold-out' position for over two years." To meet the increasing demand, Trex plans to double its manufacturing capacity by the end of the year, adding two production lines at the Winchester plant, which employs 170, and two lines at a new plant due to open this fall in Fernley, Nevada.

Trex targets a niche market, but it's a $2 billion niche. You won't find the product at Lowe's or Home Depot, Cavanna says, because the typical homeowner will look at a Trex decking board and reject it because it costs up to twice as much as treated wood.

But since Trex is used only for walking surfaces, not for structural timbers, the ultimate cost of a Trex-topped deck is only 10 percent to 15 percent more than if it were 100 percent wood.

In addition to its success in residential markets, the material now covers boardwalks at Busch Gardens, Disney World, Everglades National Park and the presidential trail at Mount Rushmore.

Trex has been accepted quickly in central Virginia, which has a reputation for being stubbornly old-fashioned, says Richie Siewers, vice president of Siewers Lumber & Millwork in Richmond. "It fits our niche well, which is a high-end market. It looks better than wood, especially after the wood has weathered, and it doesn't have to be sealed every year. You just sweep and clean it occasionally."

Although Trex advertising doesn't emphasize the product's environmental advantages, the company estimates that more than half of all the plastic grocery bags recycled in America become Trex lumber. The company advises retailers and users of wood products on how to set up recycling programs for plastic and sawdust.

Formulated by Philadelphia chemist Roger Wittenberg, Trex was originally marketed as Rivenite. Then, in 1992, Mobil Chemical Co. bought the company, hired Wittenberg as technical manager and moved the operation to Winchester, where Bob Matheny became general manager and Andy Ferrari supervised sales.

The three men bought the company from Mobil in 1996 and enticed another former Mobil employee, Cavanna, to join them as CFO. Matheny is the current president; Wittenberg is in charge of research and development; and Ferrari heads up marketing.