Polyisocyanurate, also referred to as PIR, polyiso, or ISO, is a closed-cell, rigid foam board insulation used primarily on the roofs and walls of offices, health facilities, warehouses, retail and industrial manufacturing facilities and educational institutions. Because of its high thermal performance, it is the product of choice for energy-aware homebuilders and consumers.
Polyiso roof insulation offers:
- The highest R-value per inch, which means the greatest energy efficiency performance or R-value of any building insulation product on the market
- Polyiso on a roof deck significantly reduces energy costs
- Exclusive third-party, thermal performance certification
- Only high-thermal foam to meet both FM 4450 and UL 1256 fire tests
- Nationwide availability
Superior Performance in Fire Tests
Polyiso passes both the ANSI UL 1256 and FM 4450 fire tests without a thermal barrier. Polyiso, a thermoset material, stays intact during fire exposure in the ASTM E84 or “Tunnel Test.” It forms a protective char layer and remains in place during the test, thereby meeting all building code requirements and contributing to a fire-safe building.
Compressive strength refers to the ability of a rigid foam board to resist deformation and maintain its shape when subjected to a force or load. Common construction compressive strength applications require polyiso to maintain its shape during installation as well as during use. Polyiso insulation boards are available in a range of compressive strengths. The ASTM Specification of Polyiso Insulations, C 1289, states that all Polyiso products should have a minimum stated compressive strength of 16 psi. For more information on Polyiso’s compressive strength, please consult Compressive Strength.
All Polyiso insulation manufactured by PIMA members utilizes an EPA compliant hydrocarbon-based blowing agent which has zero Ozone Depletion Potential (ODP) and virtually no Global Warming Potential (GWP); it also meets both CFC- and HCFC-free specification requirements.
Other Unique Properties
- Polyiso is stable over a large temperature range (-100°F to +250°F) and can be used as a component in roof systems utilizing hot asphalt.
- Polyiso has low density, good adhesion to facers, low water absorption and low vapor transmission.
- Polyiso is not affected by oil-based waterproofing compounds, insecticides or fertilizers when properly protected.