What is composite decking made of?

Wood composite decking entered the market in the late 1990s as an alternative to traditional lumber. Composite boards presented buyers with the first opportunity to purchase decking that requires less maintenance and lasts longer than wood. As the decking industry evolved, manufacturers like Owens Corning® introduced fully synthetic lumber, first WEARDECK™ and then structural lumber for deck framing.

Read on to learn about the composition and manufacturing process of composite deck boards.

Ingredients in Composite Deck Boards

Composite lumber contains a blend of wood, plastic, and additives. The specific ingredients and ratio of wood to plastic vary brand to brand. Oftentimes, manufacturers incorporate recycled materials. For wood components, companies may use sawdust, wood chips, and other wood fibers (source).

The plastic elements regularly include polypropylene (PP), polyvinyl chloride (PVC), and or polyethylene (PE). Manufacturers finish off the formula with a range of additives that help stabilize the plastic, protect from UV damage, and color the boards.

Manufacturing Composite Decking

To create composite deck boards, manufacturers usually employ one of these two processes: extrusion or compression molding (source). In extrusion, producers mix and heat the raw materials until they become malleable then force them through an opening in the shape of a deck board.

The second practice, called compression molding, involves pouring the raw materials into a mold. Heat and pressure from the closed mold make the components into the composite decking that you see on the shelf.

The Best Decking: WEARDECK™

Composite deck boards revolutionized the decking industry, but today’s buyers can find excellent alternatives. WEARDECK™, a fully synthetic HDPE (High Density Polyethylene) decking, outperforms composite decking. It is heat-reflective and boast over two times the strength of composite boards with virtually no expansion and contraction. WEARDECK™ also provides a Limited Lifetime Warranty* and is made in Ocala, Florida.

Contact us today to talk to an expert and request OC™ Lumber samples to embark on a journey that's built to last.