ACH Foam Technologies Solves the Rigid Insulation Water Absorption Equation

By: John Cowan, Regional Sales Manager

There are several things I think we can all agree upon about rigid insulation. Performance in the field is more important than laboratory results. Stability and long-term performance of R-Values outweighs the published R-Value of the product by the manufacturer.

Until now, laboratory testing for water absorption of molded polystyrene indicated a higher water absorption rate than XPS. Recently completed laboratory tests indicates the maximum volume water absorption of molded polystyrene is 0.3%! Tests done prior to this did not take into account a drying period following the wetting period of the product.

0.3 Water Absorption

ASTM C 272 testing methods were used followed by a 24-hour drying period before measuring water absorption by volume. The 0.3 maximum absorption by volume is the same as XPS. R-Value tests were performed on samples of XPS and Polyiso obtained from major industry suppliers. The samples of XPS and Polyiso were tested periodically for R-Values over the next 3 years. The samples were tested at both 40 and 75 degrees at an accredited lab.

At 75 degrees all three Polyiso samples tested were below the published LTTR of 5.6 after 1-½ years. At 40 degrees the Polyiso actually had an R-Value less than at 75 degrees! The XPS samples were below the published R-Value of 5.0 within a month of testing. The XPS samples continued to decline in R-Value for the next several years. Compare this to the stability of the R-Value of molded polystyrene.

When you look at all the advantages of ACH Foam Technologies’ Foam-Control® PLUS+® architectural insulation: recycle content, the availability of a variety of sizes (1/2” up to 36” plus a variety of lengths & widths), stable R-Value, and costs savings up to 30%, Foam-Control® PLUS+® is the clear choice of rigid insulation.

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