Peel and stick modified bitumen, such as GAF’s product, is applied in a three-step process. First, the surface must be clean and dry to ensure proper adhesion. Next, the peel-off backing is removed, allowing the modified bitumen to be directly adhered to the substrate. Finally, a roller is used to ensure full contact and eliminate air bubbles, enhancing the bond and ensuring effective waterproofing and durability in asphalt or bitumen applications.