It is used by some builders for good reasons. It is not called foam when it is used to build homes, perhaps as a marketing strategy. Instead, it is expanded polystyrene, or EPS. This is a rigid closed-cell thermoplastic foam. It can be recycled because it is able to be mixed with virgin expanded Polystyrene and used for packaging or wall panels. Three builders have proven success with foam construction. Following are three builders proving success with foam construction.
“We work with the largest insurance carriers across the country to educate them on what our product is made of,” said Jason Rhees, the CEO at Hercutech. “Because of Hercuwall’s combination of ESP foam, steel, and concrete, there is significant savings compared to wood and because of our hurricane ratings and fire testing, it allows them to insure these projects where they wouldn’t be able to insure wood or the cost of insuring wood isn’t feasible because it has gone up astronomically.”
The system also has no design limitations.
“Everything is designed with 3D BIM modeling and proprietary software,” Rhees said. This digitized manufacturing is barcode-driven and automated. The panels are produced in the same order as they will be installed. Individual panels typically weigh 40 to 45 pounds, which can speed up construction and require less skill.”
Installers integrate concrete into a HercuWall during a new home build.
After walls are standing, the interior finish is typical drywall, and the exterior is the architect’s choice.
Hercutech leaders shared that there are considerable savings in the working hours compared to traditional materials. Additionally, HercuWall elminiates downstream steps in the construction process and reduces municipal inspections.
“We can complete 10 units with a 5-person crew every week,” he said. “The installed price is anywhere from $11 to $15 per square foot, so it is cost competitive with highly insulated wood structures.”
Plus, using HercuWall, compared to traditional materials, simplifies the steps to qualify for the Energy Star program that gives back $2,500 per door or Net Zero Ready that gives back $5,000 per door, and also can get to net zero performance easier. The R-31 rating of the wall allows for significant cost savings due to its ability to reduce the size of the air conditioner. The amount of concrete used in the HercuWall is much less than ICF. Hercuwall can replace up to 60% of wood and recycles 99% of scrap material.”
Compared to a conventional wood frame, there is up to a 70% labor reduction. The skill level of laborers also changes. The foreman of HercuWall installations is a higher-skilled worker, but he leads a team of general workers who finish the installation. The panels are simply moved into place, stood upright and screwed. The EPS foam, which is used in the construction of HercuTech, self-extinguishes when exposed to fire. “When a fire gets to it, the EPS recedes from the fire and doesn’t continue to burn.”
HercuWall has one- and two-hour fire rated assemblies. The concrete and steel walls will not burn if a fire enters the house. They remain in place for longer and give the occupants more time to escape. HercuWall was approved by the Texas Department of Insurance for high-speed hurricane zones over 300 mph wind speeds. In 2022, Hurricane Ian hit more than 30 Florida homes that had been built with HercuWall, some of which were right in the eye of it. HercuTech went to assess the damage and reported no structural damage, no flooding, no property damage, and, most importantly, no loss of life.
The EPS foam, mainly supplied by Atlas Molded Products, is coated with Strata’s mixture called Sabscrete which consist of sand, cement, glass fiber, and other additives to create a durable building shell that can go beyond the testing protocols and load standards set by the International Code Council-Evaluation Service.
“SABS exclusively relies on foam as the primary framing material, completely eliminating the use of wood, steel, or any other framing products other than foam as the main framing product in its construction,” said Amir Saebi, the vice president at Strata International Group, the creators of SABS with headquarters in Phoenix.
The company is mainly building custom homes and has little problem convincing these homeowners who want the top technology for their home to adopt a fairly unusual product.
“It’s the developers who need proof,” said Saebi. The company specializes in custom homes and has no problem convincing homeowners who want the latest technology for their home to adopt a product that is a little unusual. Strata charges a $5,500 fee to cover the costs of training, certification and tools for the course. We monitor the builders closely and visit projects throughout the first 12 months of using our products. “
Strata oversees primarily the structural aspects of blueprints during the design and permit phase. Strata is responsible for the structural aspects of blueprints, including architectural, electrical and plumbing. However, Strata’s in-house team can only assist with mechanical and civil aspects. Saebi has a 666-page document with testing examples from the Finite Element Analysis (FEA) testing that it underwent to achieve the highest quality available.
The testing is similar to what NASA and Boeing use for spacecraft. The SABS product was subject to intricate simulations that resulted in more than 150 pages of structural load calculations showing how it will respond under varying conditions, such as fire, earthquakes, and storms.
“Results of the SABS FEA can be extensive and sometimes over 100s of pages, which is why it was never made for traditional construction and why it was so hard for SABS to get through code, until the ICC-ES approval code,” he said. “If there is an earthquake, you can clearly see the loads. The simulation will show how the structure breaks down if there is too much weight. The software was developed for heavy machinery and spacecraft to simulate loads and not in a standard structure. After we proved our theory other engineers were able to bring their products to life by using the same method. The SABS did not catch fire when hit with direct flames from a flame torch. Invented by BSAF, together with SABS, it offers one of the highest fire ratings available.
“Developers are skeptical that we can meet their demands on cost,” Saebi said. They realize that the affordable price is too good to be real. Materials, regardless of structure type, remain constant at around $35 per square feet. The price includes various components such as exterior and internal walls, roofs made with the SABS System, which eliminates the requirement for a truss, and insulation. The R-value of the envelope is usually between R-75 and R-100.
With such a high R-value, homes are more energy efficient and can reduce costs. In Arizona, for example, it costs $300 on average to cool a 3,000 square foot house in July. A SABS home, however, only costs $80.
. The SABS method can also reduce labor. The lightweight foam frame reduces construction teams from up to six people plus heavy machinery to just four. Just two people can install the roof without using a crane or pulley system. The inorganic material of EPS makes it resistant to aging, insects, and mold. One small downfall of the material can be yellowing from direct exposure to sunlight, which can be quickly cleaned with a power wash and brush technique.
The SABSCRETE material offers alternatives for finishes, replacing traditional options like stucco with a smooth textured finish.
“We moved in last September 2021,” said Shirley and Tad Halladay of their new SABS home. The average price of a stick house in Southern Utah is $267 per square foot. The cost of this house was around $100 per square foot. This 3,200-square-foot house, including the 1,008 square-foot garage, cost around $310,000. The first floor has 12-foot ceilings and the second has 10-foot. “Not bad.” Not bad.”
System 3: VERO Building Systems
Florida-based Vero Homes uses structural concrete insulated panels or SCIPs that are prefabricated foam panels with an insulated core of rigid EPS between two sheets of welded wire fabric mesh. The panels are typically 4’x8″ but can be made up to 40 feet long. The panels are connected during construction and coated on both sides with concrete for additional strength.
Vero panels integrate several materials to offer strength and high performance.
Panels used for load bearing walls are generally five inches thick. The panels can withstand 200 mph winds, seismic activity up to 8 on the Richter scale, have a 2 to 4-hour fire resistance rating, and are termite-resistant.
The panels are also energy efficient, with insulation values starting at greater than R-9 and up to R-37, compared to a typical stud wall that VERO calculates to be around R-8. The panels are made from recycled and sustainable materials, and the protective concrete structure coating can last for 100 years. All of the materials also can be reclaimed and recycled when the life cycle is complete.
More detail about that VERO Building System is included in this recent article on resilient home solutions.
The future of foam
Hercutech has created a very capital efficient process to expand manufacturing plants from market to market.
“Because of manufacturing, digitization, and automation, we can set up in a matter of months at a fraction of the cost,” Rhees said.
So, more plants may be in your area soon.
A continued focus on sustainability in the built environment will make foam more popular. These systems are a great alternative to lumber, as 27% of lumber imported by the United States comes from Canada, according to the National Association of Home Builders. Canada is also experiencing some of its worst wildfires for decades. These EPS-based system can last up to 150 years.