About Polyisocyanurate (ISO) Roof Insulation
Polyisocyanurate, commonly known in the industry as ISO, is a premium rigid foam board insulation widely used in modern commercial roofing systems. It offers one of the highest R-values (thermal resistance) per inch of any insulation material available on the market, maximizing energy efficiency. ISO boards are typically faced with fiberglass or organic felt, providing an exceptionally stable and compatible substrate for adhering or fastening the roofing membrane. It is lightweight, easy to cut and handle, and compatible with most single-ply, built-up (BUR), and modified bitumen commercial roofing systems.
Frequently Asked Questions
Why is ISO insulation so popular in commercial roofing?
Its exceptionally high R-value per inch makes it highly efficient at insulating large buildings, significantly reducing commercial heating and cooling costs.
Is rigid ISO insulation fire-resistant?
It has excellent fire performance characteristics, is thermoset (won’t melt), and is often required as a component to meet strict commercial building code fire ratings.
Can ISO roof insulation absorb water if a leak occurs?
While it has a closed-cell structure, prolonged exposure to water can degrade its insulating properties and cause dimensional changes, so it must be protected by a watertight roof membrane.
How is ISO insulation installed on a commercial roof deck?
It is typically mechanically fastened with plates and screws or adhered with low-rise foam adhesives to the roof deck beneath the primary roofing membrane.
