Insulating Concrete Formwork (ICF)

Insulating Concrete Framework (ICF) systems use either lightweight twin-walled expanded polystyrene (EPS) or extruded polystyrene (XPS) in panels or blocks to create formwork walls, for in-situ concrete walls, typically 100 or 150mm thick. Once in place, the formwork is filled with ready mixed concrete and, unlike conventional formwork, is left in place to act as insulation. For basement construction, polystyrene provides good background for waterproofing barriers. Care should be taken to ensure that the specification of the waterproofing membrane and its fixing methods are appropriate for application to polystyrene.

ICF provides a cost-effective and simple solution for placing cast in situ walls; most appropriate for new build, rather than retrofit, basements.

A new build basement using ICF.