The Standard Specification covers polyolefin-based plastic wood products for use in exterior residential decking. The Specification applies to plastic wood made primarily from recycled polyolefin plastics such as high density polyethylene (PE), but may also apply to Miscellaneous plastic materials and plastic composites of non-uniform cross-section. The Specification specifies performance requirements for the product, including bending performance, thermal expansion Stability, weathering resistance, fire performance, and slip resistance, and provides a method for calculating recommended span lengths for support joist spacing. Standard values are expressed in inches-pounds, equivalent SI units are for informational purposes only, and emphasize the need for users to adhere to safety and environment practices.