Elevate's RESISTA is a high-performance polyisocyanurate (PIR) insulation board laminated on both sides to a gas-tight, multi-layered aluminum-kraft facer (AK) or mineral-coated glass fiber facer ...

"The insulation formed another combustible layer underneath which would also give off toxic fumes," he added. The type of PIR foam used, Celotex RS5000, and the brand of cladding, Reynobond PE ...