ICF Blocks

 

These are a relatively new building system that started in Australia with thermacell blocks. Generally, these systems consist of a range of wall blocks and corner blocks that are assembled onto a solid foundation, such as concrete slab or footings, to make a complete wall.

The blocks are made from expanded polystyrene foam and are hollow inside, a lot like a styrofoam besser block.

Internal plastic ties provide support across the block, as well as for holding metal rebar in place.

Building with ICFs is much like building with giant toy blocks. You assemble the blocks, fit any plumbing and electrical conduit required, and then the entire wall is filled with concrete.

The end result is a very strong wall ready for cladding or rendering.

The advantages of ICFs include short building times and an all-in-one construction system. They also provide good levels of both thermal and acoustic insulation as well as a central core of thermal mass. ICFs are a non-combustible product so are suitable for bushfire prone areas.

The main disadvantage comes at end of life when the building is deconstructed. The foam, being contaminated with render and concrete, is generally not recyclable and will end up in landfill.

ICFs are similar in cost to regular building systems and can even work out cheaper in some cases. It should be remembered that, if renovating, installation of new doors or windows in the walls will require concrete cutting equipment.