Which standard is used for structural capacities and design provisions for prefabricated wood L-joists?

The correct standard for structural capacities and design provisions for prefabricated wood L-joists is ASTM D 5055. This standard provides guidelines for evaluating the performance characteristics of engineered wood products, specifically focusing on the load-carrying capacities, design requirements, and installation methods for these prefabricated components.

ASTM D 5055 ensures that engineers and builders have a consistent reference for determining the structural integrity and reliability of wood L-joists, promoting safe and effective building practices. This standard is crucial for ensuring that L-joists can adequately support the loads to which they will be subjected in a commercial building context.

In contrast, the other standards mentioned are focused on different materials or testing methods and do not address the specific requirements related to the design and performance of prefabricated wood L-joists.