Insulating Concrete Form Foundations
Insulating concrete form (ICF) walls are concrete walls cast in polystyrene forms that remain in place after the concrete has cured (Figure 17). Most ICF walls are “flat” ICF walls, which means that the concrete is of uniform thickness over the width and height of the wall. The NBC requires that any exposed polystyrene be protected by a fire-retardant material, such as gypsum board.
Source : Canada Mortgage and Housing Corporation (CMHC)