Everbuild evbb2firehan firefoam b2 is a quick setting one part polyurethane foam with fire resistant properties the foam expands on application to up to 50 times its original volume and meets the requirements of din 4102 part 1 for construction materials class b2 once cured the foam can be cut sawn or plastered over after only one hour providing the working temperatures can and surfaces are between 43 5 to 43 25o c ideally 20o c high degree of fire rating slows down the passage of flames an