ICF CHARACTERISTICS

ENERGY EFFICIENCY

  • Minimal, if any, air leaks, which improves comfort and reduces heat loss compared to walls without a solid air barrier
  • High thermal resistance (R-value) typically above 3 K·m²/W (in American customary units: R-17[7]); this results in saving energy compared with uninsulated masonry
  • Continuous insulation without thermal bridges or “insulation gaps”, as is common in framed construction
  • Thermal mass, when used well and combined with passive solar design, can play an important role in further reductions in energy use, especially in climates where it is common to have outside temperatures swing above inside temperatures during the day and below at night.

STRENGTH

  • Insulating concrete forms create a structural concrete wall, either monolithic or post and beam, that is up to ten times stronger than wood framed structures.
  • Structural integrity for better resistance to forces of nature, compared to framed walls.
  • The components of ICF systems — both the poured concrete and the material used to make the ICF — do not rot when they get wet.

SOUND ABSORBTION

ICF walls have much lower rates of acoustic transmission. Standard thickness ICF walls have shown sound transmission coefficients (STC) between 46 and 72 compared to 36 for standard fiberglass insulation and drywall. The level of sound attenuation achieved is a function of wall thickness, mass, component materials and air tightness.

FIRE PROTECTION

ICF walls can have four- to six-hour fire resistance rating and negligible surface burning properties. It is worth pointing out that the International Building Code: 2603.5.2 requires plastic foam insulation (e.g. Polystyrene foam, Polyurethane foam) to be separated from the building interior by a thermal barrier (e.g. drywall), regardless of the fire barrier provided by the central concrete. Forms made from cement bonded – wood fibers, polystyrene beads, or air (i.e. cellular concrete) have a fire rating inherently.

INDOOR AIR QUALITY

Because they are generally constructed without a sheet plastic vapor barrier, ICF walls can regulate humidity levels, mitigate the potential for mold and facilitate a more comfortable interior while maintaining high thermal performance. Foams, however, can give off gasses, something that is not well studied.

ENVIRONMENTAL SENSITIVITY

ICF walls can be made with a variety of recycled materials that can minimize the environmental impact of the building. The large volume of concrete used in ICF walls has been criticized, as concrete production is a large contributor to greenhouse gas emissions.

VERMIN

Because the entire interior space of ICF walls is continuously occupied (no gaps as can occur between blown or fiberglass insulation and a wood frame wall) they pose more difficulty for casual transit by insects and vermin. Additionally, while plastic foam forms can occasionally be tunneled through, interior concrete wall, and the Portland cement of cement-bonded type forms create a much more challenging barrier to insects and vermin than do walls made of wood.

BUILDING CODES

Because of the technical characteristics of ICF walls, the single process of building walls with ICFs is more efficient than the old 6 stage process using stick framing. ICF buildings meet or exceed national building codes and save time and money in the process.