In Type IV construction, what is the minimum requirement for cross-laminated timber thickness in floors?

In Type IV construction, which is also known as heavy timber construction, cross-laminated timber (CLT) plays a significant role due to its structural properties and fire resistance characteristics. The minimum thickness requirement for cross-laminated timber in floors is set to ensure adequate structural performance, safety, and fire resistance.

A minimum thickness of 4 inches for CLT floors is designed to provide sufficient strength to support the loads expected in commercial buildings. Thicker panels contribute to enhanced performance in terms of deflection limits and load-bearing capacity. Additionally, a thickness of 4 inches helps enhance fire resistance, which is crucial in Type IV construction where large timber members are more exposed to fire risk.

Considering alternative thicknesses, options that suggest lower panel thicknesses, such as 2 inches or 3 inches, would not fulfill the necessary structural and fire safety requirements, while a choice of 5 inches exceeds the minimum required thickness, making it unnecessarily heavy and potentially more expensive without added benefit. Hence, the choice of 4 inches appropriately matches the balance between structural integrity and practicality for Type IV construction.