Wood plastic composite stair tread
This proposal adds a new requirement to IBC that wood plastic composites increasingly used as exterior decks boards, stair treads, handrails, and guards be rated for performance criteria. This proposal also adds a definition for wood plastic composites and adds the appropriate ASTM reference standard to the code. The IBC is currently silent on these materials despite their growing acceptance for deck construction.
The addition of labeling requirements for wood plastic composites will ensure safe application of these materials in exterior deck systems. The referenced standard, ASTM D7032, includes performance evaluations such as flexural tests, ultraviolet resistance tests, freeze-thaw resistance tests, bio-deterioration tests, fire performance tests, creep recovery tests, mechanical fastener holding tests, and slip resistance tests. The standard also includes considerations of the effects of temperature and moisture, concentrated loads, and firepropagation tests.
Wood plastic composite material manufacturers who seek to provide quality materials currently demonstrate compliance with the intent of code requirements in the IBC through the use of evaluation reports. Requiring these materials to be approved through testing to the ASTM standard by approved laboratories and labeling by approved quality assurance entities will ensure that the code requirements for structural and fire safety issues are met. This code proposal also provides the industry with additional options for demonstrating compliance.