TIMCO 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 and DIN4102-1 for use in fire safety critical applications requiring up to 4 hours fire resistance. Ideal B1 Grade.Excellent thermal & acoustic information.Up to 30x expansion.Fast curing – 2 hours.For 30 and 60 minute fire door applications, use Fire & Acoustic Seals Fire Door Foam (FAS-750G).