In November 2017, the Polyisocyanurate Insulation Manufacturers Association (PIMA) issued an updated bulletin addressing job-site storage of polyisocyanurate insulation. Suppliers and users of polyisocyanurate roof insulation should be aware of this bulletin, as well as manufacturers' instructions and NRCA's guidelines.
PIMA Technical Bulletin #109, "Storage and Handling Recommendations For Polyiso Roof Insulation," provides some guidance about job-site storage of polyisocyanurate roof insulation.
The bulletin indicates polyisocyanurate insulation typically is shipped protected by a plastic wrap, plastic bag or both. The factory packaging is intended for handling in the manufacturing plant and during transit. You should not rely on factory packaging as protection at job sites or other outdoor storage locations unless otherwise specified by the manufacturer.