Closed-cell polyurethane spray foam
Closed-cell SPF is the structural layer of the system. It goes on at a minimum 1 inch nominal thickness in a single seamless pass, adheres directly to the prepared deck, and forms a vapor barrier and an insulating layer at the same time. The closed-cell structure (as opposed to open-cell) is what makes the foam resist water absorption and hold up to foot traffic for inspection and maintenance.
Manufacturer warranty: SPF foam carries a material warranty from the foam manufacturer covering density, adhesion, and cell integrity per their terms. The Roof Boyz install includes the manufacturer documentation at project close, registered to your address.

