How is difference between modified bitumen and built up roof applied in asphalt or bitumen modification processes?

Modified bitumen and built-up roofs (BUR) differ primarily in their application and composition. Modified bitumen is created by adding polymers to asphalt, enhancing flexibility and durability, and is typically applied in rolls using torch or adhesive methods. In contrast, BUR consists of multiple layers of asphalt and reinforcing fabrics, providing a robust, layered system. While modified bitumen offers ease of installation and better performance in extreme conditions, BUR provides a traditional, reliable roofing solution with excellent waterproofing properties.