Physical Properties of EPS

Click link for printer-friendly EPS Properties table: EPS Physical Properties. Return to this page by clicking on your browser's back button.


See ASTM-C578-08b standards for test methods.

All values based on data from Flint Hills Resources, Styrochem International, NOVA Chemical Corporation and BASF Corporation.

Federal Trade Commission Ruling: Use the 75 F R-Value when calculating R-Values for residential construction.

Design Considerations:

DO NOT COMPARE polyisocyanurate conditioned R-Values by RIC-TIMA and PIMA to EPS R-Values by ASTM C-578.

  • ASK for a 20 year 100% R-Value Warranty.
  • Flammability: Like many construction materials, EPS is combustible.  It should not be exposed to flame or other ignition sources.  Current model building code requirements should be met for adequate protection or seperation from occupied areas.
  • Water Absorption Properties: EPS water absorption is low.  Moisture takes the path of least resistance and travels around individual beads rather than through them; the non-interconnecting cell structure prevents capillary absorption.
  • Water Vapor Transmission: EPS has low permeability but is not considered a vapor barrier.

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Phone 605-886-8084     Toll-free 800-658-3444     Fax 605-886-8099

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EPS is a lightweight, versatile, economical, recyclable material that can be tailored to meet changing and complex requirements. Select one of the following topics to learn more:

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