B1 Fill & Fix Expanding PU Foam - Gun GradeTIMCO B1 fire rated fill & fix expanding foam is a premium quality fire resistant polyurethane based expanding foam formulated to give excellent performance in a majority of fire critical applications. The complex cell structure also gives the foam excellent thermal and acoustic characteristics. Tested in accordance with BS 476 20, EN1366 4, EN13501 and DIN4102 1 for use in fire safety critical applications requiring up to 4 hours fire resistanc 4