A lower grade, reinforced kraft paper bitumen-bonded, laminate made to BS 1521, class B1F. This is our traditional reinforced kraft paper bitumen-bonded building paper laminate used within the construction industry which meets the requirements of BS 1521, grade B1F (Class B with reinforcement). Unlike many other recent developments in building membranes (eg breathable roof underlays), BS 1521 does not give guidance on suitable use, and as such this product is a generic material, serving a wide range of end-user defined applications. However, typical usage for B1F has naturally evolved over time including for example, separation layers for insulated screeds, bond breaks, temporary protection and garden buildings. Novia B1F meets the technical requirements of BS 1521 (Class B with reinforcement) for water-proof building papers, utilising polymer reinforcing scrim to increase strength and general product performance. Typical uses Separation layers for insulated screeds, bond breaks, temporary protection and garden buildings. Propertes Length: 50m. Width: 1.25m. Roll size: 62.5m2. Upper temperature stability: over 70C. Liquid water resistance minimum: 3 hours. Chemical resistance: resistant to chemicals found in plaster & cement. Biological: does not attract insects or vermin. Grade: B1F. Certification: BS 1521.