Posted on August 18, 2022
Insulated concrete forms (ICFs) continue to establish a beachhead in an ongoing battle of building materials. The continuous insulation and thermal mass of ICFs deliver desired energy efficiency. Occupants value quiet, comfortable surroundings more than ever.
Insulated concrete forms (ICFs) continue to establish a beachhead in an ongoing battle of building materials. The continuous insulation and thermal mass of ICFs deliver desired energy efficiency. Occupants value quiet, comfortable surroundings more than ever.
Natural disasters also drive interest in resilient concrete construction. Images of ICF homes still standing after direct hurricane hits prove persuasive. In 2018, Hurricane Michael lashed the Florida panhandle with 140 mph winds. The beachfront community of Mexico City was ground zero. There, an ICF home was the only one remaining for blocks around.
Common Myths Debunked
Any new way of doing things meets with resistance. It is inevitable. For years ICF construction ran headlong into the preferences of architects and builders. Many were simply more comfortable with wood-frame construction. Today, ICF construction is more mainstream than ever. ICF construction has come a long way in recent years. Efficiencies accrue as contractors gain experience with ICFs.
Let's look at some myths remaining to this day.
ICFs are just for residential foundations
A quarter-century ago, this was mostly true. Today, it is possible to substitute an ICF walls for most wood-frame, CMU, or even tilt-up walls. ICFs are routinely used to construct K-12 schools, college dorms, theaters, hotels, houses of worship, and much more.
As Building Design + Construction notes, “Building teams are specifying ICFs for mid- and high-rise structures." In 2017, developers announced plans for a 16-story mixed-used high-rise in Mount Vernon, NY.
ICF construction is too expensive
Lifespan costs of ICF vs. wood-frame homes have long been competitive. This is due in large part to how long they last. ICF construction tends to support asset values and therefore resale values.
Lumber’s price instability also drives interest. The dramatic price spike in May 2021 re-focused some homeowners on ICF construction. At the time, lumber costs ran $15-20,000 or more for a new home.
A well-insulated cavity wall is just as good
ICFs yield walls with thermal mass and continuous insulation. Building codes typically distinguish between ICF walls and wood or steel cavity walls. An ICF wall delivers airtight, continuous insulation. While it is possible to achieve this with a cavity wall, extra steps are required.
Its thermal mass further reduces both heating and cooling costs. A 2019 ICFMA test reveals that an R-23 ICF wall easily outperforms an R-20 cavity wall with five inches of continuous insulation added. Once it reached steady state, the mass wall performed 58% better than its cavity counterpart.
Installation is challenging
Reports of blowouts during concrete pours are largely a thing of the past. However, as with all construction methods, disciplined ICF installation is essential.
Embrace proper pre-pour preparation. Only install ICF blocks that are in pristine condition. Stack blocks per manufacturer recommendations. Ensure the same with horizontal and vertical rebar reinforcement. Brace and strap openings, block cuts, and penetrations. Double-check bracing before the pour.
Perform a slump test, adding a half-inch of slump when concrete is pumped under pressure. Proper ratios in the concrete mix ensure workability while managing pressure on the ICF walls.
Finally, plan your pour before the concrete truck arrives. During the pour, move in one direction around the structure. Never shoot concrete directly at an ICF. Let the concrete flow naturally, pushing it at a 45-degree angle through the forms.
Case Studies – 2022 ICF Builder Awards
ICF Builder recognizes ICF projects across a host of residential and commercial categories. Each of the following award winners highlight key advantages of ICF construction.
White Residence – Warwick, RI
The White residence is the ICF Builder 2022 winner in the Small Residential category.
The urban residential environment made it a prime candidate for noise-resistant ICF construction. The three-story, flood-compliant home features 10,158 sq ft of six-inch Amvic ICFs. The $352,000 project features three free-standing concrete floors covering 28 x 43 ft each.
Thirty-one of the 34 windows offer views of Narragansett Bay. The heating system shuts off for nine hours per night. Still, indoor temperatures remain within a two-degree range.
Future XPress Car Wash – Rohnert Park, CA
Car washes consume significant energy and water resources. The Future XPress Car Wash is in Rohnert Park, CA. It combines ICF construction with state-of-the-art energy and water conservation technologies. The heat recovery system provides more energy-efficient drying.
The owner wanted a structure that would hold up in a wet environment. Noise attenuation was another priority. A passive geothermal shell made of 100% ICFs. addressed both. The million dollar project covers 6,389 square feet. It required 19,827 sq ft of IntegraSpec and InsulDeck ICFs. Installation of the ICFs took 120 days.
Spinieo residence – Chalfont, PA
The Omnia Group designed the Spinieo residence in Chalfont, PA. It is a $2.4 million, 14,800 sq ft home featuring ICF construction. It was First Runnerup in the 2022 ICF Builder Awards’ Unlimited Residential category.
The English Gothic Revival home is clad in granite. Turrets along the front edifice invoke a castle-like feel. Various arches illustrate ICF compatibility with curved surfaces. Inside, hand-carved stone mantels appear beneath ceilings soaring from 11 to 28 feet. Construction spanned two years. Installation of the 24,000 sq ft of Fox Blocks ICFs required 100 days.
About PACA
The Pennsylvania Aggregates and Concrete Association (PACA) uses this website to highlight the latest industry innovations for members as well as the general public.
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