ACH Foam Technology Gives Specifiers,
Installers More Reasons to Choose EPS

Foam-Control Plus+ architectural grade EPS insulation is now configured for easy, across the board comparisons with similar XPS products. That's possible because of three industry-first innovations from its manufactuer, ACH Foam Technologies:

1. Foam-Control Plus+ has become the first in the EPS market to provide face labeling, which makes comparisons between EPS and XPS more accessible. The stamp shows UL certification information, ASTM type, compressive strength, R-value, product name, whether it’s scored, and if it contains a termite resistant treatment.

“Although XPS has offered face stamping since nearly the inception of the insulation, EPS hasn’t until now,” said Frank Kiesecker, ACH Foam Vice President, architectural products. “The face label on ACH’s Foam-Control Plus+ architectural grade insulation makes it easier for distributors to stock product and easier for contractors to know what they’re paying for. This in turn provides peace of mind to specifiers that the correct product was delivered to the jobsite.”

2. Foam-Control Plus+ is the first EPS insulation with a warranty for 100% of its R-value for 50 years. Regardless of thickness, density or application, the warranty is the same. Foam-Control Plus+ is available in R-Values of R-5, R-7.5, R-10, R-15, R-20, and R-30. Other EPS manufacturers typically offer 100% for 20 years; XPS manufacturers can only offer a 90% R-value due to off-gassing, which decreases its R-value over time.

3. Foam-Control Plus+ is the first EPS insulation in the market to come pre-scored. The scoring provides contractors and installers the ability to break apart sections on the jobsite, giving them more flexibility, saving installation time, and reducing jobsite waste. Although the XPS market has offered this benefit for years, pre-scoring helps Foam-Control Plus+ more effectively compete with XPS products. The 4’ x 8’ sheets of Foam-Control Plus+ allow for three scored widths: 16", 2', and 4'.

There is much competition among polystyrene insulation manufacturers for the below-grade, under slab, and cavity wall insulation market. Claims made by the XPS industry are conflicting with that of EPS manufacturers. The validity of some claims are debatable. Specifiers, architects and contractors appreciate the opportunity to make well-informed decisions.


EPS Resin Bead

To thoroughly understand the difference between EPS and XPS insulations, it’s useful to begin with a look at their similarities:
-- Both are comprised of polystyrene resin
-- Both use trapped air as their long-term insulating medium
-- Both have a closed-cell structure
-- Both fall under the same manufacturing standard: ASTM C578 Standard Specification for Rigid, Cellular Polystyrene Thermal Insulation. The ASTM C578 standard includes 14 different types of polystyrene. The different classifications relate directly to physical characteristics of each type – most notably, the density, compressive resistance, and R-value.

What makes EPS and XPS different is their manufacturing processes. EPS uses steam and the blowing agent pentane to expand polystyrene resin beads and subsequently mold them into blocks, which can later be cut to size. XPS, on the other hand, processes melted polystyrene resin through an extruder and expands it, using blowing agents.

There are key differences between EPS and XPS — most importantly, moisture resistance, environmental impact, long-term R-value, compressive strength, panel sizes, and cost per R-value.


Moisture resistance is an important issue for architects, contractors and specifiers to consider when selecting below-grade, cavity wall and under slab insulations. Claims by the EPS manufacturers on moisture resistance are conflicting with those made by the XPS industry because one source is using real-life field testing and the other is using controlled laboratory testing.

The XPS industry prefers a controlled under water test, submerging the XPS for a relatively short period of time, depending upon the type of XPS tested and the test parameters. Usually the submersion time is somewhere between 2 and 24 hours. In this scenario, XPS appears to win over EPS because it resists water absorption in the near-term quite well. However, as the XPS takes in moisture more slowly than EPS, it also releases it very slowly.

“We believe nothing is more real than an actual installation dug up and tested after 15 years in the ground,” said Kiesecker. “A 15-year field study demonstrates actual performance in the ground after 15 years. The results show dramatic differences in the performance of the two insulation types.”


Environmental impact: EPS has never contained HCFCs. Environmental advocates also note that EPS uses no dyes, and can contain up to 15% recycled content. The XPS industry, with highly competitive subgroups, has used pink, blue and green dyes as branding elements. In addition, the limited amount of recycled content in XPS varies widely by product and by company.

Long Term R-Value is affected by off-gassing. Off-gassing occurs when blowing agents present in XPS are released over the lifespan of the product and are slowly replaced with air, which then becomes the insulating medium. As the off-gassing occurs there is a loss of R-Value.  This differential is evident in the disparate EPS/XPS industry warranties: The XPS industry offers a 90% R-value warranty due to the product’s off-gassing. The EPS industry, on the other hand, offers a 100% R-value warrantee. ACH Foam Technologies is the first in the EPS industry to offer a full 50-year warranty for 100% of the stated R-value.


Compressive strength and panel sizes:

Although both XPS and EPS are available in compressive strengths of 15, 25, 40 and 60 psi, XPS also comes in 100psi. If the job requires 100psi compressive strength, it needs XPS. Because of market dominance, XPS is more widely available from distributors and in the insulation marketplace as a whole.





  8”, 12” 16”, 24”, 36”, 48”

    16”, 24” or 48”


  2’, 4’, 8’, 9’, 10’ or 16’



  1/2” to 36”

      ¾”, 1”, 1-½”, 2”, or 3”
  • EPS is available in a wider variety of panel sizes and thicknesses.
Foam-Control Plus+ is also the first EPS insulation to come pre-scored. The scoring provides contractors and installers the ability to break sections apart at the jobsite for added flexibility, reduced installation time, and less jobsite waste.
Cost per R-value: EPS costs 10% to 30% less than XPS per equivalent R-value and compressive strength. ACH Foam Technologies has made it easier for contractors and specifiers to access this information.


Foam-Control Plus+ In Action:

Pat’s Tire built a new store in Chilton, Wisconsin. The new building would double operating space and reduce energy use. Architect Steve Klessig of Keller, Inc. specified Foam-Control Plus+ insulation for under slab and footings. “A key feature of Pat’s new store is in-floor heating. A closed loop system of tubing carries hot water throughout the concrete slab,” explained Klessig. “I know that EPS allows below-grade moisture to escape and retains its full R-value. The soil under the slab isn’t great; we couldn’t risk losing heat down into the ground. Secondly, I chose Foam Control Plus+ for its bearing capacity. This high density product will support a heavy inventory of tires.”

Project manager Cory Vander Wettering added, “Our number one reason for choosing this insulation was its performance with underground moisture. In addition, custom sheet sizes made installation a breeze and the product came in at a great price.”

Denver healing center "The Green Herb" celebrated 20 years of helping heal the community with herbs by expanding its building to 9000 square feet and offering additional therapies. According to contractor Farley Lozowick of Arch Form, the insulation was chosen with specific regard to containing the heat in the concrete slab, not letting it move downward into the earth. “There’s a forced air heating system in the building and this will put less stress on that. The installation went really smooth. We simply spread it out, tacked it down and then put the wire mesh on top.”

ACH Foam Technologies recycles 100% of its post-industrial EPS and is actively involved in recycling post-consumer EPS as well. With locations throughout North America, ACH has over four decades experience in EPS manufacturing, with products for construction, geotechnical, packaging, and industrial applications.

For specifications, technical data and studies see or call ACH Foam Technologies at 800.525.8697.


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