Insulating concrete forms (ICF) is a relatively new method of construction that is finding a strong following with home owners and businesses alike that are interested in energy efficient structures. ICF construction can be utilized throughout a structure, from foundation walls through to concrete ceilings.
The basic premise with ICF construction is the use of heavy-duty foam blocks that interlock to form a wall. These blocks are then secured with continuous rows of rebar. The forms are then situated in place and filled with a continuous pour of concrete. The resulting wall is typically 12 inches thick consisting of a core of 6 inches of reinforced concrete and 2-3 inches of the insulating rigid foam on both the interior and exterior of the finished wall. As you might guess, this wall is incredibly strong, and resilient to high winds and extreme temperatures.
The finished structure is able to be finished using traditional finishing materials. On the exterior walls stucco, siding, or bricks can be installed, and on the interior drywall or plaster can be utilized. The interior plumbing and wiring are put in place by the plumber and electrician cutting channels in the interior foam and running their wires and pipes.
Here are some of the advantages of ICF homes:
Energy efficiency: Several studies have proven that ICF homes can reduce energy costs by as much as 50%. The poured walls provide a very good thermal mass which moderates the inside temperature, and less demand on HVAC units. It also can reduce the size of the HVAC unit required to heat and cool the space.
Weather resistance: ICF structures are extremely strong. When these structures are engineered to meet specific needs, such as tornado or hurricane resistance, they have proven to be significantly stronger than wood framing. They are also insect resistant (there is no wood to attract termites), and therefore no harmful chemicals to kill termites. Additionally, ICF homes also provide superior resistance to fire; some studies indicate up to four times as much as wood framing.
Lower homeowner insurance: Due to documented studies of weather resistance, insurance companies can offer lower premiums.
Environmentally friendly: A typical 2,000 square foot house requires about 50 trees’ worth of lumber. An ICF house can be made entirely of cement and steel. The blocks are also formaldehyde free, which provides very good interior air quality.
The cost of ICF structures can vary depending upon design requirements, material and labor cost, and interior and exterior finishes. Typically, an ICF structure will run between 1-8% more than traditional wood framing. These costs are usually recouped rather quickly with energy and insurance savings.