This is a 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. 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. Key Features: Bitumen, paper and reinforcement scrim laminate Lowest cost reinforced product Roll sizes 1.25m x 50m Multi-use adaptable building product Made to BS 1521 Class B Note: Novia products are non returnable if over or incorrectly ordered