Insulating Concrete Form Foundation

Insulating concrete form (ICF) foundations are made up of two polystyrene faces held apart by permanent plastic or metal spacers and are being used increasingly in Canada.

When concrete is poured into the space between the polystyrene faces, they provide both permanent formwork and insulation for the concrete wall. The polystyrene eliminates the need for form stripping and promotes curing.

For housing applications—foundations not supporting more than two floors with a maximum floor-to-ceiling height of 3 m (10 ft.)—typical concrete thicknesses range from 140 to 240 mm (51⁄2 to 91⁄2 in.). The reinforcing required is dependent on the wall thickness and the height of the backfill supported by the wall. The connection of the ICF foundation wall to the wood-frame floor (Figure 43) is similar to that of the cast-in-place concrete wall without polystyrene forms. Where an ICF foundation supports a masonry wall, the top of the ICF may be flared and reinforced to accommodate the masonry.

Figure 43

Insulating concrete form foundation

Source : Canada Mortgage and Housing Corporation (CMHC)