Several factors influence the performance of modified bitumen roofs in asphalt or bitumen modification systems. Key factors include the type of polymer used for modification (such as APP or SBS), the quality of the base bitumen, the application method (torch-applied, self-adhered, or cold adhesive), environmental conditions during installation, and the roof’s exposure to UV radiation and temperature fluctuations. Additionally, proper substrate preparation and maintenance practices significantly impact the longevity and effectiveness of the roofing system.