Polyisocyanurate (ISO)

Polyisocyanrate, often referred to as “Polyiso,” is a rigid foam board insulation bonded to facers on both sides. Polyiso provides a higher R-value per inch compared to other insulations commonly used in commercial and residential construction.

Polyiso has four primary components: MDI (methylene diphenyl diisocyanate), polyol, flame retardant, and a blowing agent (pentane). When combined and catalyzed, a chemical reaction ensues which causes the blowing agent component to boil. The pentane vapors expand which creates gas-filled cells, generating the high R-value.

Common applications include roofing, walls, and ceiling insulation. The use of pentane as a blowing agent has a negligible global-warming potential. With the lowest global warming potential among insulation options, a high energy saving, and its contribution to building resilience, polyiso serves as the most sustainable option for the insulation of commercial and residential buildings.

Polyiso Quick Facts

  • R value range of 5.9 to 6.5 per inch of foam
  • Outstanding performance in fire tests
  • cost-effective and sustainable
  • minimizes space, material, and labor requirements
  • improves service-life of roofs and walls
  • Low density, good adhesion to facers, low water absorption, and low vapor transmission
  • Not affected by oil-based waterproofing compounds, insecticides or fertilizers when properly protected
  • Cold weather affects the R-value, as temperature decreases, R-value decreases as well