Everbuild Fire Foam B1 Gun Grade is a quick-setting fire rated, one part polyurethane foam, and expands on application to yield up to 50 times the can contents. Fire rated up to 4 hours in certain joint configurations. For use with an Everbuild Professional Foam Gun, once cured the foam can be cut, sawn or plastered over after only one hour. It will fill irregular and broad gaps where most conventional fillers would fail, and possesses insulating, and sound deadening properties. Fire Foam meets the stringent requirements of DIN 4102 Part 1 for Construction Materials, Class B1 and BS 476 Part 20 Size: 750ml.