The pre-teen phase is awkward—a confusing period between childhood and the teen years. Composite decking, introduced in the early 1990s as an alternative made of wood fiber and recycled or new plastic, is approaching this period like a typical Tween with high expectations and unprecedented growth, but also unresolved issues.

Composite decking—touted for its low-maintenance and long-lasting attributes—controls 15 percent of overall decking sales. Although pressure-treated wood continues to dominate, composite's predicted annual growth of 15 percent to 20 percent rivals that of the hungriest teenage boy.

At the onset of this product category in 1997, there were only a handful of manufacturers and few with national distribution. Now, nearly 40 manufacturers offer the product, although distribution varies, according to industry experts.

One reason for composite decking's soaring popularity is its low-maintenance attributes. Although they need periodic cleaning, composite products don't have to be stained or painted like treated lumber. Also, composites don't splinter, split, or rot; they provide good traction; and they don't overheat in the sun like traditional wood decks, manufacturers contend.

Another explanation for composite decking's ascent is that color choices are flourishing with the increased competition. Early planks faded to light grays and browns, but now deeper, richer colors that maintain their good looks also are available. Trex, for example, offers an exotic wood composite collection, Brasilia, that mimics ipe and amber.

“Five or six years ago, the introduction of color composites boosted the appeal,” says Al Terry, owner of New York City-based New York Decks. He has installed composites for 10 years.

Because some new composite decking colors are bolder and darker, they're more prone to absorbing heat and fading faster. But encapsulation technology, as well as UV inhibitors and additives, are addressing these issues, manufacturers say.

New styles, too, are sprouting up. Manufacturers are producing boards that have wood-grain and brushed looks, offering demanding consumers more choices. Also, hidden fastener systems are simplifying installation and providing cleaner appearances.

What's more, a portion of composite decking's growth can be credited to public outcry about lumber treated with CCA that contains arsenic. CCA-treated wood now is banned for residential use, replaced by higher-priced lumbers treated with other chemicals.

But like most building products and materials, composite decking isn't without concerns. Composites cut like regular lumber, but installation may be trickier, installers contend. Mike Proscia, owner of Frame to Finish in Montville, N.J., says that composite decking is heavier than pressure-treated wood, which translates to longer installation times, he says.

It's accepted that all outdoor products are susceptible to environmental conditions, but manufacturers are attacking mold prevention differently. For example, CertainTeed's Boardwalk line features a chemical additive, biocide, which combats mold and mildew growth, says John Pruett, marketing manager for composite decking and railing. Maureen Murray, a spokeswoman for Trex, the category originator, says her company has improved its manufacturing process and formulation, which now incorporates several anti-mold elements.

Correct Building Products' new CorrectDeck CX with SafeGuard's co-extrusion process combats mold and mildew because all exposed surfaces are encased with an antimicrobial coating, according to the firm. The manufacturer also says SafeGuard helps resist staining and color fading.

All manufacturers promote proper board installation so gaps allow for moisture drainage.