Recycled wood/plastic composite lumber typically consists of a 50/50 mix of wood fibers from recovered saw dust and waste plastics that include high-density polyethylene, PVC, and others. The material is formed into both solid and hollow profiles.

Recycled wood/plastic composites are typically more rigid than 100 percent recycled plastic lumber because the wood fibers act as reinforcement. In addition, the plastic encapsulates and binds the wood together to resist moisture penetration and degradation from fungal rot.

Some recycled wood/plastic lumber products can weigh considerably more than standard lumber products. Like other plastic products, recycled wood/plastic lumber can become more flexible in hot weather and more rigid in cold weather than other decking materials.

Known by a number of brand names, this durable blend of wood fibers and plastic weathers without disintegrating, maintains its shape, does not shrink or expand, and will last the lifetime of the residence. These plastic-wood composite products compare favorably with traditional pressure-treated wood decking and typically come paintable or stainable in brown and gray. Composite decking weathers, like wood, but will age to an even tone without deteriorating. It is dimensionally consistent, won't splinter, has no knotholes, is completely rot-resistant, and requires no annual sealing. Composite decking lacks the strength of wood, however, and won't span the same distances as wood. With appropriate structural support, composite decking is well suited to first floor and above-ground decks. Plastic structural beams are not readily available in all markets and tend to make the deck bouncy, so pressure-treated wood is most commonly used to support this type of decking.