Critical Evaluation of Existing Specifications for Polyisocyanurate (ISO) Foam Insulation Boards in Roofing Applications

Abstract

Abstract In North America, more than 50 % of low slope roofing applications uses faced rigid cellular polyisocyanurate (hereafter abbreviated as ISO) board as thermal insulation. Long-term performance of a roof assembly is critically dependent on the ISO characteristics during the service period in various environmental conditions. For this reason, the ASTM C 1289-02, “Standard Specification for Rigid Cellular Polyisocyanurate Thermal Insulation Board,” outlines the physical and thermal property requirements for the ISO boards. However, these requirements are based on the available knowledge, information, and consensus at the time of drafting and balloting of the ASTM standard. Nevertheless, the standard gets updated and revised when more credible data are available that solicits revisions of the current standard. This paper presents experimental results from an ongoing pilot research study that critically evaluates the ASTM C 1289-02 specification requirements for the ISO on three engineering properties: (1) dimensional stability, (2) thermal resistance, and (3) compressive strength. Preliminary results from this study reveal many unknown phenomena, particularly regarding the dimensional stability and compressive strength of ISO boards.