What technical requirements define two ply modified bitumen roofing system for asphalt or bitumen modification?

A two-ply modified bitumen roofing system requires specific technical standards, including the use of polymer-modified bitumen sheets, typically reinforced with fiberglass or polyester for enhanced durability. The system must comply with ASTM D6162 or D6878 standards, ensuring proper adhesion and flexibility. Additionally, installation requires a minimum thickness of 180 mils, with appropriate heat-welding or adhesive methods to ensure watertight seams. Proper surface preparation and drainage considerations are also essential for optimal performance and longevity.