Fiber-cement subfloor guides

Start with the construction type

Almost every question about non-combustible subfloor resolves once the construction type per level is settled. IBC Chapter 6 sorts buildings into Types I through V, and Types I and II require building elements to be non-combustible — a property established by passing ASTM E-136, not by a fire-retardant treatment or a Class A flame-spread rating. If the floor deck sits in a Type I or II level, wood-based panels are out and the material question is already answered.

The second question is the assembly, not the material: does the floor/ceiling need an hourly fire-resistance rating, and which listed design achieves it? A rating belongs to a tested assembly — deck, framing, fasteners, and ceiling membrane together — so the design number matters as much as the panel. Cost comes third, and it is only meaningful as a delivered figure compared across complete assemblies.

Who these are written for

Architects and specifiers confirming a code path before it reaches the AHJ, general contractors pricing a rated floor assembly, and developers weighing a non-combustible deck against a wood alternative on multifamily, hotel, and light-commercial projects. Each guide leads with a direct answer, states the standard or code section behind it, and links to the issuing authority so the claim can be checked rather than taken on trust.

JARA supplies the underlying UL assembly references, ASTM reports, and evaluation-report documentation as a submittal package on request. For the product itself, see High Performance Subfloor.