This concrete-composite lumber is rated for direct contact with water or soil and is fire-resistant, according to its manufacturer, the Concrete Lumber Co. A 2x8 can span up to 60 inches, nearly four times the typical 16-inch span of many kinds of synthetic and wood decking. Boardwalks made with concrete decking can carry loads of 125 pounds per square foot, according to the company.
The material—a patented cementitious composite mixture that the company says is “stress reinforced”—can be cut using a circular saw and diamond blade. Decking and framing is assembled with standard deck hardware and concrete screws (not nails). The company says it is working with hardware and fastening manufacturers to develop better installation methods.
Planks are 60% heavier than pressure-treated lumber; a 16-foot 2x6, for example, weighs 80 pounds.
Suggested retail prices (for 16-foot lengths) include $105 for a 2x14, $96 for a 2x12, and $70 for a 2x8. The lumber carries a 25-year residential warranty.
Concrete Lumber is currently manufactured in New Jersey, but the company is hoping to open additional manufacturing sites this year.