The Limitations of Insulating Concrete Forms

Concrete Forms

• Insulating concrete forms -- also known as ICF systems -- involves concrete forms, such as walls or slabs made with built-in insulation materials. Combining concrete and insulation materials within the same mass or form provides increased thermal resistance in terms of preventing heat from passing through concrete materials. Insulated concrete forms consist of hollowed-out foam insulation blocks with concrete poured inside. The foam blocks include steel rod supports, which reinforce the structure of the blocks. With the large amounts of concrete required to manufacture insulated forms, ICF systems place an added strain on environmental resources in terms of the large amounts of energy required to manufacture concrete materials.

Costs

• The use of exterior foam blocks creates an aesthetic effect that enables insulated concrete forms to appear the same as the materials used in traditional home or building construction. And while ICF systems can help to reduce a home’s overall heating and cooling costs, the process required to manufacture insulated concrete forms poses a cost limitation when compared to other construction materials. On average, a home built using insulated concrete forms costs anywhere from 2 to 7 percent more than a home built from wood or stone. In terms of average pricing, a square foot of ICF materials runs from $2 to $3. This price does not include labor costs, concrete pouring or exterior finish applications.

Expertise

• The manufacture of insulated concrete forms requires several steps to make a finished, usable product. In general, three different methods produce three different types of concrete forms. The flat system method uses a solid mass of concrete inside a foam insulation casing. The grid system method produces a waffle pattern effect across block surfaces with different thickness of concrete throughout. The post-and-beam system uses a criss-cross pattern of concrete that’s interconnected with foam insulation materials. Not surprisingly, a certain degree of expertise is required to manufacture and build with insulated concrete forms. As a result, contractors unfamiliar with the design process may charge higher costs than contractors who work with ICF systems on a regular basis.

Insulation Gaps

• Insulated concrete forms provide a sturdy, insulating material when used as backing for drywall on homes with brick, stucco or lap siding exteriors. As the foam insulation appears on the outside of an insulated form, gaps in the insulation material can leave surfaces exposed to damaging effects. Insulation gaps provide ready access for insect to nest. Gap areas can also take on groundwater, which creates a whole set of potential problems. Groundwater access means insulation materials become subject to moisture, humidity and also freezing effects. When this happens, insulation and concrete materials can deteriorate over time as moisture and potential mold growth eat away at concrete form materials.