Technical Information

The following documents provide more detailed technical information and facts regarding various applications using extruded polystyrene foam insulation products.

Extruded Polystyrene Delivers Higher R-Values than Expanded Polystyrene in Below-Grade Applications, According to New University of Alaska Fairbanks Study

XPS Insulation Performance, Below Grade Series ID: IP-BG-01
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EPS-Reported Long Term Below-Grade Insulation Performance Study is Debunked

The long term below-grade insulation performance study published by the EPS Industry Alliance (EPS-IA) is not well-supported and is inconsistent with previous significant research in this field. Please read more in XPSAís comprehensive rebuttal to this study.
Read the PDF -- United States
Read the PDF -- Canada

Comparison of XPS and EPS Foam Insulation Board Products

Extruded polystyrene foam insulation (XPS) and expanded polystyrene insulation (EPS) are similar, but have many important differences. XPS is the superior product when considering R-Value, moisture resistance, thermal performance, and compressive strength.
Read the PDF -- United States
Read the PDF -- Canada

To read more about selecting polystyrene foam in situations where moisture exposure occurs, please read the following article from The Construction Specifier.
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XPS Demonstrates Performance Superior to EPS under Extreme Environmental Cycling Conditions

The moisture absorption data published in the EPS-IA Below-Grade Series 104 Technical Bulletin, February 2014, demonstrates that EPS absorbs more moisture than XPS products in multiple lab procedures. Read more in XPSAís response about how moisture absorption will directly reduce an insulationís in-service effective R-value.
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XPS Tech Talk Documents


XPS Sheathing Franklin/APC Life Cycle (pdf)

How-To Design Guide for Installing Foam Sheathing (pdf)

Design Supplement for How-To Design Guide (pdf)

Roof Systems

Sustainable R-Value with XPS Roof Systems (pdf)

Protecting Against Solar Heat Damage in XPS Roof Systems (pdf)



About XPSA

The Extruded Polystyrene Foam Association (XPSA) is a trade association representing manufacturers of Extruded Polystyrene Foam (XPS) insulation products and the industry's raw material suppliers. XPSA members collectively manufacture more than 95% of all XPS destined for use in the North American market. XPSA promotes the benefits that accrue to society from appropriate use of XPS foam insulation applications.

© Copyright 2016 The Extruded Polystyrene Foam Association

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