Icf Insulated Concrete

Limitations

ICFs may be used for either above- or below-grade walls. The comparative benefits and limitations of ICFs must be considered in light of the systems which it might replace. In the United states, foundation walls are typically cast-in-place (CIP) concrete or CMU (block) walls, whether for basements, crawls spaces, or stem walls. For above-grade walls, the predominant construction is some variation of wood-framing. The discussion below uses these typical construction types as the point of comparison.

Limitations: Foundations

ICFs can be used for full basements, crawlspaces, or as stem walls for slabs. Possible limitations of ICFs when compared to block (CMU) or cast-in-place (CIP) concrete foundations include:

If building codes prohibit the use of foam below-grade, alternative methods must be chosen or the foam form removed after the concrete cures.

Construction costs may be higher.

For those entering the business, initial investment for ICFs is cheaper than traditional forms, but life cycle cost of ICFs versus traditional forms may be higher because ICFs are not reusable.

Because EPS allows termite trails to exist undetected, a gap in the polystyrne may be required to facilitate detection. Some regional codes merely require termite shields; sometimes at the footing and transition from ICF to frame construction junction.

Limitations: Above-Grade Walls

Possible limitations of ICFs when compared to wood framing include:

Higher total cost.

Additional engineering in homes not meeting the application limits of the Prescriptive Methods

Difficulty gaining code acceptance, although the Prescriptive Method and IRC 2000 inclusive of prescriptive methods should alleviate this issue over time.

Possible significant time needed to research various products and manufacturers

Overcoming the training/learning curve

Difficulty of making alterations such as accommodating larger windows, either during original construction or remodeling.

Impact on design. Because ICF walls are heavier than wood-framed walls, design changes may be necessary to ensure an ICF wall is placed directly over another load-bearing ICF wall. If the design cannot be changed, wood framing can be combined with ICF construction.

Thickness of walls impact overall dimensions, door and window installation, and use of extension jambs.

Impact on scheduling. The need to ship forms (pending establishment of broader distribution network) may require longer lead-time.