EPS = Proven Performance

Expanded polystyrene insulation guarantees stable R-Value and increased energy savings.

Expanded polystyrene (EPS) insulation products have been the subject of extensive research and evaluation over a 30-plus year lifespan in a wide variety of building and construction applications. 

EPS is a closed-cell, thermal plastic material produced from styrene and pentane that can be engineered to meet the specific requirements of commercial, residential, and civil engineering projects. Building owners and contractors recognize the value of EPS due to its unique physical properties and cost savings.

Another Energy Crisis?

During the 1970s, demand for quality building insulation soared when an oil crisis sent heating and cooling costs skyward. In recent months, this same phenomena demands building owners look for even more energy-efficient insulation products. Offering stable R-value, EPS is made up of 95-percent air, making it an excellent insulating material. It can be produced in a wide range of densities and thick-nesses to provide the physical properties and thermal performance required for an application.

The Institute of Research in Construction, a subdivision of the National Research Council of Canada, Ottawa, Ontario, conducted a two-year study, “The Exterior Insulation Basement System” on the performance of EPS in below-grade applications. The results concluded “the key performance factors of thermal conductivity and compressive strength of the EPS specimens were not affected by the 31-month in-situ exposure.” In fact, it demonstrated a slight increase in its thermal performance during the second year. This groundbreaking research establishes a new baseline for EPS performance measurements.

Other studies, looking at newer EPS building systems applications like insulated concrete forms (ICFs) and structural insulated panels (SIPs), show increased energy savings over competing materials, up to 25 percent. In a recent test conducted by the Florida Solar Energy Center, Cocoa, FL, a building structure constructed with EPS tested at only 1.8 air changes per hour (ach) vs. 3.9 ach measured for the more antiquated construction type.

Code Advancements

New code developments are also paving the way for increased cost savings when using EPS. Recent fire testing and evaluation reports from some national and state building code authorities make EPS foam insulation even more cost effective when used in steel-deck roofing applications.

The Seymour High School Aquatic Center in Seymour, WI, saved thousand of dollars in roofing construction costs by switching to UL-classified EPS. “We saw an opportunity to save the school district some tax dollars without compromising the safety or performance of the building,” says Troy Eick, co-owner of Northeastern Roofing Inc. “Because the Wisconsin building code authority recognized the direct application of polystyrene to steel deck roof assemblies — without the need for a thermal barrier — EPS foam was the most cost-effective insulation choice. We were able to save the school district nearly $20,000.”

In January 2000, the International Conference of Building Officials (ICBO) issued evaluation reports approving the use of expanded polystyrene foam plastic insulation for use in roofing systems directly applied to steel roof decks. The Southern Building Code Congress International Inc. (SBCCI) issued similar evaluation reports in 1997. 

With ongoing code developments and technological advancements for new uses of expanded polystyrene, its role as a cost-competitive and high-performance insulation material is expected to increase in upcoming years. Growth projections in ICFs and SIPs alone are in
the 20 to 25 percentile. With escalating energy costs, it is more important than ever that building owners seek out materials that deliver consistent performance over the life of the building.

Betsy de Campos is executive director of the EPS Molders Association, Crofton, MD, a partner of EPA ENERGY STAR.

Environmental Bonus

Pentane is the blowing agent used in the manufacture of EPS, and is not harmful to the Earth’s stratospheric ozone layer. In fact, Green-peace recognizes EPS as a viable and preferred insulation technology. While pentane dissipates over a brief curing time — within a few days — hydrochlorofluorocarbons (HCFCs) remain within the cellular structure of the foam, for possibly five to 10 years or more, according to the Tennessee Technological University, Cookeville, TN, Therefore, the use of HCFCs can cause a significant loss of R-value, estimated at up to 28 percent.

SOURCE: EPS Molders Association.