Insulated Concrete Forms - ICF F.A.Q.
FREQUENTLY ASKED QUESTIONS ABOUT OUR ICF WALLS
Q: What are Insulating Concrete Forms (ICF)?
A: Insulating Concrete Forms (ICF) are hollow blocks or panels made of EPS (expanded polystyrene) plastic foam that construction crews stack into the shape of the exterior walls of a residential or commercial building. Workers then add reinforcing steel and fill the gap (typically 4” to 8”) between the two layers of foam with concrete, which cures and hardens into a monolithic core. The foam panel stays in place. This combination of concrete, steel and foam creates an incredibly strong and energy-efficient structure.
Q: What is Expandable Polystyrene (EPS)?
A: EPS is manufactured from expandable polystyrene beads containing a blowing agent and flame retardant additive. Steam heat expands the blowing agent to produce moisture-resistant, multi-cellular particles, which increase about 40 times their volume during this process. Over an intermediate phase the beads lose their moisture, blowing agent condenses out and air diffuses into cellular structure. After the air has been stabilized, the multi-cellular particles, pre-expended beads are thermally steam fused into blocks and after they cured they are cut into slabs, sheets or other shapes. EPS insulation can be molded in a range of densities to meet specific application requirements.
Q: Does Expandable Polystyrene (EPS) provide moisture resistance?
A: EPS in not a vapor barrier; it is relatively permeable and its uniform closed-cell structure allows diffusion of moisture. Because it does not trap water vapors within the exterior walls, it does not need costly venting and absorbs the moisture from the concrete preventing cracking.
Q: How does the homeowner benefit from this type of construction?
A: Homes built with ICF offer resistance to natural disasters such as tornadoes, hurricanes, earthquakes, fires and floods. ICF can dramatically reduce heating and cooling bills, plus provide an exceptionally comfortable and quiet indoor environment.
Q: What are the design possibilities and/or limitations with ICF?
A: Today’s concrete homes can be created with virtually any design or architectural feature. Our company offers many different floor plans, elevations and can customize them or build for any client’s taste. The result is a home that looks like any other structure in the neighborhood but has all the benefits of solid concrete construction.
Q: Does customer pay more to build this way?
A: No, actually our prices are competitive with regular concrete block or frame construction. Florida Green Homes, LLC., as an experienced ICF contractor, strives hard to provide the most superior product for your home. Additionally, you achieve significantly lower utility and energy bills, insurance savings and downsizing of heating and cooling equipment.
Q: What is the average R-value of ICF walls?
A: The equivalent R-value performance of ICF consists of three factors. First is the R-value of the expanded polystyrene. Second, the thermal stability of massive concrete walls reduces the temperature fluctuations and, consequently, the heat load requirements that are images to wood-frame buildings. Finally, air leakage (infiltration) can account for 20 to 40 percent of the heat load requirements of a wood-frame building. ICF eliminate this air infiltration through the wall assembly. As a result, with the combined performance of the R-value of the expanded polystyrene, the stabilizing effects of the thermal mass of the concrete, and the reduced air infiltration, ICF walls actually perform as high as R-47, or more in some areas of the country.
Q: What about comfort?
A: Concrete walls built with ICF effectively buffer a house’s interior from the outdoors. The thick ICF sandwich of a massive material (concrete) with a light one (foam) sharply cuts fluctuations in temperature, air infiltration and noise. ICF keep the inside more comfortable and less drafty than ordinary wood-frame walls. With regard to noise, studies have shown that compared to a typical wood-frame house, only about one-third as much sound penetrates an ICF wall.
Q: Why is Florida Green Homes, LLC. home is a healthier environment for you and your family?
A: Fewer pollutants are penetrating into the interior of the home because of our method of moisture resistant construction and will discourage mold growth. Mold is a major component in making allergies and asthma unbearable.
Q: How do ICF homes resist tornado and hurricane-force winds?
A: Debris driven by high winds presents the greatest hazard to homeowners and their property during tornadoes and hurricanes. Recent laboratory testing at
Q: Is this building technique approved by code organizations?
A: Yes. Every major code organization in the
Q: Why is ICF considered an environmentally friendly method of building?
A: Florida Green Homes, LLC. is recognized by the Florida Green Building Coalition, Inc. During a building’s life cycle (from construction to demolition), the greatest ecological impact is the amount of fuel needed to heat and cool the home. Insulating Concrete Homes are a preferred environmental choice because of significant savings in natural resources needed to maintain a comfortable temperature.
Q: How well do ICF walls hold up in a fire?
A: Experience shows that concrete structures are far more likely to remain standing through fire than are structures built of other materials. Concrete does not break down until it is exposed to thousands of degrees Fahrenheit — far hotter than a typical house fire. In “firewall” tests, ICF walls were subjected to continuous gas flames and temperatures of up to 2,000°F for as long as four hours. None of the ICF walls ever failed structurally, in contrast to wood-frame walls, which typically collapse in one hour or less.
Q: Won’t the foam burn or give off harmful emissions?
A: The foams in ICF’s are manufactured with flame-retardant additives. The National Research Council reviewed the numerous existing studies of fire emissions and concluded that the emissions from polystyrene foams are no more toxic than those of typical softwoods used in home construction.
Q: Can termites eat through the foam in an ICF wall?
A: Expanded polystyrene (EPS) has no nutritional value to insects, including termites. If left exposed and untreated, they may attempt to nest in the EPS foam. Foam is approved for use below grade, as well as above grade, by all building codes as long as “an approved method” of protecting the foam plastic and structure from termite damage is provided.
Q: Will it take longer to build my home with ICF’s?
A: No. Building ICF homes actually take less time than using wood-frame construction. The ICF construction method eliminates several steps, such as sheathing and insulating the exterior walls that are necessary with wood-frame construction.
Q: How does our construction method improve the home value?
A: As energy costs rise, you can bank on the fact that your lower heating and cooling costs will become an important resale feature. The Appraisal Journal conducted studies demonstrating the increasing value a home has by becoming more Energy Efficient . By including Energy Efficient upgrades, the home’s value can increase by approximately $20 for every $1 reduction in annual utility bills.