Core and shell composite structural member

A deck board comprising a rectangular cross section profile having the form of dimensional lumber, the deck board comprising:

• (i) a shell comprising a polyvinyl chloride and fiber composite material, comprising about 10 to 50 wt. % fiber, the balance comprising polyvinyl chloride, the shell having a thickness of about 0.5 to about 3 mm;
• and
• (ii) a core, surrounded by the shell, comprising thickness of at least 0.5 mm, a polyvinyl chloride foam, with a density of 0.1 to 1 g-cm-3;
• wherein the deck board has locus for a fastener for anchoring the deck board to a structure, the deck board having a width of about 5 to 30 centimeters, a thickness about 1 to 3 centimeters, a length of less than about 10 meters, and the core is free of one or more formed structural support member.