C-joists and cement board Type IB construction type?

[charlottejra]

Hello! We are working on a new construction 4-story residential building and the structural system is c-joists and cement board. We are trying to find out if it's possible at all, by reinforcing the assembly design to reach higher fire rating, to upgrade the entire building system to Type IB? Understanding c-joists and cement board are typically categorized as Type IIA by construction type (as defined in BC Chapter 6, particularly table 601). But if all required fire ratings are met in Table 601, for example, the primary structural frame, floor assembly, are all 2 hours rated. Does that mean the system can be classified into Type I?

Our initial thought was that the structural members must be fire-resistive by their own (as opposed to non-combustible as in Type II). But also wondering if the differences between Type I and II in Table 601 are purely defined by the hours, not materials.

Thank you for any thoughts and input!

 

[classicT]

2021 IBC 602.2 Types I and II​

Types I and II construction are those types of construction in which the building elements specified in Table 601 are of noncombustible materials, except as permitted in Section 603 and elsewhere in this code.