Insulating concrete forms

ICFs are basically formwork blocks or panels of expanded polystyrene (EPS).

The ICF blocks can be likened to giant Lego blocks. The foundation is created by interlocking the blocks to build exterior and interior wall. Reinforcement bars are usually placed between the walls before concrete is poured in.

Although ICFs have been in use in Europe since the 1960s it was only during the past 10 years that ICFs caught on in North America, according da Silva.

“ICFs appear to have a lot of good qualities, but many builders and workers are not familiar with it,” he says. “It has not been around long enough for people to trust that it will provide a last- ing foundation.”

ICF’s market share is steadily grow- ing, according to Greg Doren, product manager of Plasti-Fab Ltd., a provider of EPS products. The company sells the Advantage ICF system brand.

“ICFs were traditionally used in commercial buildings, offices, hotels, schools and hospitals,” he says. “Today we are seeing a lot more single and multi-family homes.”

For homeowners, the main bene t of ICF systems is improved insulation. The EPS provides built-in insulation that cuts energy used for heating by up to 50%.

A typical 8” concrete foundation with a 2”x4” wood frame and R-8 insulation can provide an effective R value of 8.8, while an Advantage ICF system will achieve an R value of 22.8, according to the company.

ICFs enable builders to use up to 40% less concrete than other cement-based foundations. The simplicity and speed of install- ing ICF blocks can reduce construction time by as much as 80%. Concrete also cures much faster and be er inside ICFs, says Doren.