The minimum thickness for cross-laminated timber in timber floors of Type IV construction is ______ inches.

In Type IV construction, which pertains to heavy timber construction, cross-laminated timber (CLT) plays a significant role in providing structural integrity and fire resistance. The minimum thickness for CLT used in timber floors is established to ensure that the material meets specific strength and fire safety requirements.

A thickness of 4 inches is necessary because it offers the appropriate balance of structural support and fire-resistance characteristics critical for safety and compliance with building codes. The regulations for Type IV construction emphasize the need for a minimum thickness that can endure various loads and provide adequate performance during exposure to fire.

This standard is essential not just for structural soundness but also for resisting fire spread, which is a crucial aspect of safety in commercial building design. Therefore, a minimum thickness of 4 inches for cross-laminated timber in these floors ensures that the building adheres to the necessary safety codes and performance criteria.