Blistering in modified bitumen roofing is influenced by several key process parameters. These include the temperature during the application, which affects the viscosity and adhesion of the bitumen; the rate of cooling, which can lead to thermal stresses; and the quality of the polymer modification, which impacts flexibility and resistance to moisture. Additionally, the substrate preparation and environmental conditions during installation play crucial roles in preventing blister formation. Proper control of these parameters is essential for optimal performance.