Insulated Concrete Forms

Insulated Concrete Forms

Insulating concrete forms (ICFs) result in cast-in-place concrete walls that are sandwiched between two layers of insulation material. These systems are strong and energy efficient. Common applications for this method of construction are low-rise buildings, with property uses ranging from residential to commercial to industrial. Traditional finishes are applied to interior and exterior faces, so the buildings look similar to typical construction, although the walls are usually thicker.


Overview & History

Insulating concrete forms, or ICFs, are forms used to hold fresh concrete that remain in place permanently to provide insulation for the structure they enclose. Their history dates back to after World War II, when blocks of treated wood fibers held together by cement were used in Switzerland. In the 1940s and 1950s, chemical companies developed plastic foams, which by the 1960s allowed a Canadian inventor to develop a foam block that resembles today’s typical ICFs. Europeans were developing similar products around the same time.In the 1980s and 1990s, some American companies got involved in the technology, manufacturing blocks and panels or planks. By the mid-1990s, the Insulating Concrete Form Association (ICFA) was founded to do research and promotion of the products, working toward building code acceptance. They also worked with the Portland Cement Association to build awareness of this type of construction. Although there were some obstacles—costs could be greater than frame construction because people didn’t understand the system, builders had to work closely to get code approval, and materials were proprietary—the number of insulating concrete forms producers grew. As a result, competition increased and costs moderated.

The new companies developed variations and innovations to distinguish one system from another. Over time, some ICF manufacturers consolidated, leading to a smaller number of larger companies. Because insulating concrete forms systems offered performance benefits like strength and energy efficiency and were initially more expensive to construct, the first target market was high end home construction. Custom home clients were willing and able to pay extra for the premium quality. As word of ICFs grew and innovations reduced manufacturing and installation costs, builders began using the forms for mid-price-range homes. Some production builders now create entire large developments using insulating concrete forms.

In the past, single family residential accounted for about 70 percent of ICF construction—versus about 30 percent for commercial or multifamily uses—but the products are suitable for all these applications, and larger buildings appear to be a growing market for ICFs. They have become popular for a variety of commercial projects including apartments or condos, hotel/motel, retail, and even movie theaters.

Easy to Construct

ICF homes and offices are a snap to build. They combine framing, insulation, and sheathing into one easy step. The lightweight prefabricated polystyrene blocks are laid out in the shape of the wall to be formed, and stacked up like Lego blocks to achieve the desired height.The blocks create a hollow wall that is reinforced with steel for additional structural support. Concrete is poured into the forms in the final step and the polystyrene is left in place to provide insulation. Electrical wiring and plumbing is easily embedded in the forms using a router or hot knife.

Beauty and Design Flexibility

ICF homes can be constructed to suit your tastes and imagination. They are appropriate for starter homes or the home of your dreams. Curves and angles are easier to build with ICFs than other framing systems, and concrete’s strength can be used to create large open spaces. So it’s up to you: Ante Bellum or Modern, Mediterranean villa or French chateau, a quiet weekend retreat or a palace for entertaining friends and family.Once your architectural decisions are made, the true beauty of ICF homes is apparent. The polystyrene becomes a construction surface that can be covered with any exterior finish (brick, stucco, vinyl siding) and interior finish (sheetrock, plaster, paneling) you want. The only differences you’ll notice between a regular and an ICF home are all the features and benefits of the ICF house after you move in.

Energy Efficiency

Because of the excellent insulating properties of the polystyrene forms and the thermal mass of the concrete, residential and commercial ICF structures are very inexpensive to heat and cool. Annual savings estimates range from 20% to 50% over conventional homes.Due to the thermal mass of the concrete, temperatures inside an ICF structure do not fluctuate as widely as they do in other construction. That means a more comfortable environment that requires fewer heating and cooling cycles and less energy. Good for your wallet, good for the environment.

Storm Protection

Reinforced concrete walls help shelter your family from the damaging winds and flying debris of tornados and hurricanes. The reinforced structure of ICF walls have been shown to withstand high winds and the impact of missiles moving up to 150 mph.If you already have a home or business you may be interested in building an ICF safe room for weather emergencies. These safe rooms can be retrofitted to existing structures and often take the form of walk-in or storage closets. The walls and ceiling are reinforced concrete that offers excellent protection from Mother Nature’s fury.

Fire Resistance

Experience shows that concrete structures are more likely to remain standing through fire than are structures built with other materials. Concrete doesn’t burn. It doesn’t soften and bend. Concrete doesn’t break down until it reaches thousands of degrees Fahrenheit – temperatures that are uncommon in most structural fires.ICF walls are much less likely to burn than other types of framing systems. The polystyrene is manufactured with flame retardants that stop the foam from supporting flames – the material tends to melt away rather than burn – and it is approximately five times better than wood at stopping flames from spreading from materials burning in close proximity.

That means an extra margin of safety for your family, customers, and employees.

Low Maintenance

ICFs are virtually impervious to rot and termites, two of the most common causes of home repairs. There is no wood in an ICF wall, and that means there is nothing to deteriorate or for termites to feed on.

Peace and Quiet

The same insulating properties that make ICFs so energy efficient, also makes them a haven from the outside world. The excellent thermal insulating properties ICFs offer become an acoustical barrier as well.Studies have shown a reduction in outside noise of up to 66% compared to conventionally framed structures. That means its perfect for providing quiet workspace in busy commercial and industrial areas and a peaceful retreat from noisy traffic, neighborhood children, dogs, and powered lawn care tools.

Improved Air Quality

Concrete homes can help you breathe easier. Some of the things that make ICF houses and buildings so energy efficient and quiet are the increased material mass and uniform material distribution. The interlocking foam faces and continuous concrete in the center also make insulating concrete form walls exceptionally airtight.This means drafts are cut sharply, sound waves don’t penetrate, and air borne pollutants are kept at bay. Studies have found that ICFs have only one-third to one-half as much air infiltration as a traditionally framed home.