Blue or Pink or Yellow or White?

By:  Pat Austin, Sales Representative – Architectural Products

Rigid foam insulation products are manufactured using a variety of plastic resins and other compounds, but if you’re like me you tell them apart visually by their color. Extruded polystyrene (XPS) is usually blue or pink. Polyisocyanurate (ISO) is typically yellow, but sometimes has a foil or grey paper facer adhered to it. Expanded polystyrene (EPS) is almost always white.Foam-Control Plus+ Below-Grade Insulation

While color is the easiest method of distinguishing these products, for below-grade applications, there is more to the story than meets the eye. How each product performs when exposed to bulk moisture is a critical indicator of its effectiveness. Short-term laboratory testing would lead you to believe that XPS has the lowest water absorption in the field. However, recent 15 year in-ground moisture resistance testing has contradicted these claims. Regardless of how much water a rigid foam insulation absorbs, the question we need to answer is this: How much R-value remains? That is the question that matters as we try to heat and cool our buildings.

As it turns out BASF Corporation, perhaps the world’s largest producer of styrene monomer (the raw material used in production of both XPS and EPS), answered this question back in the early 1990’s. They tested 2″ XPS and EPS to see how much water each could take on while maintaining set R-value levels (94, 92, 90 and 87 percent). The differences are dramatic. EPS can absorb over 14X the moisture volume of XPS, and maintain 94% of its R-value.  Read the BASF E2 Document.

Foam-Control Plus+ architectural grade EPS insulation is available in several grades (150, 250, 400 and 600) and thicknesses up to 40″

That is performance in action. No matter how you color it.

About Pat Austin

BSIE from Marquette University in 1986, MSMSE from UW Madison in 1989. General contractor for 13 years before joining the ACH Foam team in 2007. Married to Kelly, with four sons.
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2 Responses to Blue or Pink or Yellow or White?

  1. Don says:

    What colors other than white does EPS insulation for roofs, walls, & foundations come in?

    • Mary A. Burk says:

      The natural color of the raw material is white. No color additives are used to make EPS insulation unlike XPS which adds color for branding purposes. We will be releasing a new product soon that is silver-gray in color called graphite polystyrene (GPS). The material is impregnated with graphite giving it the gray color. The graphite reflects radiant heat giving it a higher R-Value.

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