For roof construction in Type IV, glued-laminated arches must have members at least ______ inches nominal in width.

In Type IV construction, which is often referred to as "Heavy Timber" construction, the regulations emphasize the use of substantial wood members to provide structural integrity and resistance to fire hazards. When it comes to glued-laminated arches, the requirement that the members must be at least 6 inches nominal in width ensures that the structural components are robust enough to support the loads they are designed to carry while also adhering to fire safety measures embedded in building codes.

Wood members that are thicker provide greater fire resistance, which is particularly important in Type IV buildings due to their heavier timber construction. The 6-inch minimum width strikes a balance between structural reliability and compliance with safety standards, improving the overall performance of the roof system under various conditions, including potential fire exposure. This width also facilitates better construction techniques and ensures the longevity and durability of the wooden structures used in commercial buildings.