Spray Polyurethane Foam

Spray polyurethane foam, often called spray foam insulation, is a two-component liquid plastic that is mixed and sprayed on site, where it expands and cures into a rigid or semi-rigid foam that both insulates and air-seals a building envelope in a single application, unlike batt insulation, which insulates without sealing air gaps. Developed from mid-twentieth-century polymer chemistry and in widespread construction use since the late twentieth century, its closed-cell form offers a higher insulating value per inch than most other common insulation materials along with structural rigidity and moisture resistance, making it popular for retrofits and irregular cavities that batt insulation cannot easily fill.