Insulating concrete form
The first expanded polystyrene ICF Wall forms were developed in the late 1960s with the expiration of the original patent and the advent of modern foam plastics by BASF.
"[1] It is right to point out that a primordial form of ICF formwork dates back to 1907, as evidenced by the patent entitled “building-block”, inventor L. R. Franklin.
Forms made from cement bonded – wood fibers (eg[9]), polystyrene beads (e.g.[10][11]), or air (i.e. cellular concrete – e.g.[12]) have a fire rating inherently.
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.
Consideration must also be given to the understanding that the load-bearing part of an ICF wall is the concrete, which, without special preparations, does not extend in any direction to the edge of the form.
Less-skilled labor can be employed to lay the ICF forms, though careful consideration must be made when pouring the concrete to make sure it consolidates fully and cures evenly without cracking.
Brick and masonry facades require an extended ledge or shelf angle at the main floor level, but otherwise no modifications are necessary.
Depending on the experience of the contractor and their quality of work, improperly installed exterior foam insulation could be easy access for groundwater and insects.
To help prevent these problems, some manufacturers make insecticide-treated foam blocks and promote installation of drainage sheeting and other methods for waterproofing.
A hot knife or electric chainsaw is commonly used to create openings in the foam to lay piping and cabling.
Versions of simple carpentry tools suitable for cement-bonded type forms are made for similar use with autoclaved aerated concrete.
ICF construction can allow up to 60% smaller heating and cooling units to service the same floor area, which can cut the cost of the final house by an estimated $0.75 per square foot.
ICF buildings are less expensive over time, as they require less energy to heat and cool the same size space compared to a variety of other common construction methods.
Additionally, insurance costs can be much lower, as ICF homes are much less susceptible to damage from earthquakes, floods, hurricanes, fires, and other natural disasters.
[22] In seismic and hurricane-prone areas, ICF construction provides strength, impact-resistance, durability, excellent sound insulation, and airtightness.
ICF construction is ideal in moderate and mixed climates with significant daily temperature variations, in buildings designed to benefit from thermal mass strategies.
[25][26] ICF buildings may be more difficult to remodel than conventionally framed structures because specialized tools and methods are required to cut the concrete walls.
