What do insulated concrete form walls offer that wood-framed walls can’t, in terms of comfort, performance, affordability and safety? Keep reading as there are some compelling benefits, according to statistics from ICFA and PCA.
Lower Energy Bills
Homes built with ICF walls require about 44 percent less energy to heat and 32 percent less energy to cool than a comparable wood-frame house, based on a study of 58 single-family homes located throughout the United States and Canada.
Half had exterior concrete walls constructed using ICFs and the other half were comparable neighboring houses with wood-frame walls. All the houses were less than six years old. The energy savings come from the outstanding insulating values for ICF walls (as high as R-40, compared to wood-frame’s R-9 to R-15 values) and tighter construction.
Those who live in ICF homes say the absence of cold drafts and unwanted noise are the biggest pluses, even topping the energy-saving benefits. Houses built with ICF walls have more even air temperatures and are far less drafty. The barrier formed by the foam-and-concrete sandwich cuts air infiltration by as much as 75 percent when compared with a typical frame house. The high thermal mass of the concrete also buffers the home’s interior from extreme outdoor temperatures, while the continuous layer of foam insulation minimizes temperature fluctuations inside the home by eliminating the cold spots that can occur in frame walls along the studs or at gaps in the insulation.
The forms are equally effective at keeping out loud noises. The greater mass of concrete walls can reduce sound penetrating through a wall by more than 80 percent when compared to stick-built construction. Although some sound will still penetrate the windows, a concrete home is often two-thirds quieter than a wood-frame home.
ICFs and concrete are also an unappealing food source for termites, carpenter ants or rodents that often dine on or reside in wood-framed walls, which makes your home basically pest free.
Healthier Indoor Environment
ICF walls contain no organic material, so they won’t support the growth of mold, mildew and other potentially harmful microorganisms. They also reduce the infiltration of air that can bring in outside allergens.
The polystyrene foam used in many ICF walls is completely nontoxic and free of formaldehyde, asbestos and fiberglass. In tests of the indoor air quality in ICF homes, no harmful emissions were detected. In areas where radon is a concern, ICF foundation walls help to minimize the leakage of radon gas into homes.
Safe Haven from High Winds
Homeowners and builders in hurricane- and tornado-prone areas, including those rebuilding after Hurricane Katrina, are increasingly turning to concrete structural walls to stand up to fierce storms that would otherwise level a wood-frame home.
Tests have shown that ICF walls can withstand flying debris from tornadoes and hurricanes with wind speeds of up to 250 mph. And the Federal Emergency Management Agency recommends ICF construction for building tornado-resistant safe rooms.
Insurance companies recognize concrete as being safer than any other form of construction when fire threatens a home. The plastic foams used in ICFs won’t add fuel to a fire because they are treated with flame retardants to prevent them from burning.
In fire-wall tests, ICF and concrete walls withstood continuous exposure to intense flames and temperatures of up to 2,000 degrees Fahrenheit for as long as four hours without structural failure, compared with wood-frame walls that collapsed in an hour or less.
Less Repair and Maintenance
Because ICF walls use non-biodegradable materials, they are not vulnerable to rot or deterioration as is untreated lumber. The reinforcing steel, which is buried in and protected by the concrete, won’t rust or corrode.