ASTM International

Standard Specification for Establishing Performance Ratings for Wood-Plastic Composite and Plastic Lumber Deck Boards, Stair Treads, Guards, and Handrails
 N D7032

Annotation

This specification covers the procedures to establish a performance rating for wood-plastic composite (WPC) deck boards. This specification also defines the procedures to establish a performance rating for WPC guards and handrails. The purpose of this specification is to establish the basis for code recognition of these products or systems in exterior applications where combustible construction is allowed (see X1.1).

NOTE 1—While WPCs may contain wood fiber, the presence of wood fiber in the composite is not required by this standard. Other lignocellulosic materials may be used. For WPC deck boards and guardrail systems evaluated according to this standard, the structural, physical, and fire attributes may or may not exhibit similarity to those of wood due to the presence, type, and quantity of plastic(s) in the composite. WPCs should not be assumed to behave similarly to wood. For example, to address the influence of plastic in the composite, special considerations in the standard address sensitivity to temperature, ultraviolet (UV) exposure, and freezethaw resistance.

The plastic component of wood-plastic composites and plastic lumber covered by this specification shall consist primarily of thermoplastics.

Deck boards, stair treads, guards, and handrails covered by this specification are permitted to be of any code compliant shape and thickness (solid or non-solid).

A deck board, and a deck board used as a stair tread, are assigned a span rating indicating its ability to comply with model code specified functions identified for its specific end use. A guard or handrail is recognized for its ability to meet minimum code requirements specified in the appropriate model building code.