720.2.1 Facings.
BC § 720.2.1
Where such materials are installed in concealed spaces in buildings of Type III, IV or V construction, the flame spread and smoke-development limits do not apply to facings, coverings, and layers of reflective foil insulation that are installed behind and in substantial contact with the unexposed surface of the ceiling, wall or floor finish. Exception: All layers of single and multilayer reflective plastic core insulation shall comply with Section 2614.













