What is Flash and Batt?

The flash-and-batt method of insulation combines a layer of spray foam insulation with conventional fiberglass batts. The installation method can be used for floors, walls, or roof assemblies.
Closed-cell spray polyurethane foam insulation has several desirable characteristics. It’s an excellent air barrier, an excellent vapor retarder, and it has a high insulating value per inch (about R-6).