In Type IV construction, how close can the lumber in sawn or glued laminated plank floors extend to walls?

In Type IV construction, which typically involves heavy timber framing for commercial buildings, there are specific regulations regarding the clearances of structural elements such as lumber. The correct clearance for lumber in sawn or glued laminated plank floors extending to walls is set at 1/2 inch. This requirement is crucial because it allows for necessary expansion, contraction, and movement of the wood without risking damage or compromising structural integrity.

This 1/2-inch clearance helps to prevent moisture-related issues, such as rot or warping, which can occur if the lumber is placed too closely against walls. Additionally, proper spacing contributes to fire safety by ensuring that there is a gap that can help slow the spread of fire and allow for proper ventilation. Such building codes and standards are established to ensure the safety, longevity, and performance of structures, particularly in commercial applications where wood is a primary material.