Fan fold insulation is a flexible, accordion-folded sheet of expanded polystyrene (EPS) foam used as an additional insulation layer on commercial re-roofing projects. It installs directly over an existing roof surface, creating a smooth, even substrate for the new membrane while adding thermal resistance to the assembly. The folded format allows it to ship compactly and unroll quickly across a large roof deck.
On a commercial reroof, fan fold insulation solves two problems at once: it smooths out surface irregularities in the existing roof so the new membrane lays flat without stress points, and it improves the overall R-value of the assembly to bring it closer to current energy code requirements. It is commonly used on recover projects where a full tear-off is not in the plan but the owner needs to meet updated insulation standards.
Sentry Roofing uses fan fold insulation as part of recover systems where the existing deck and substrate are sound. We confirm compatibility with the new membrane system and manufacturer warranty requirements before specifying it for a project.
Ready to add this to your building? Request an evaluation from Sentry Roofing and we will put together a solution for your facility.
