Membranes can come in different forms like PVC, TPO, or EPDM. you can learn more about those in our article: TPO vs PVC. But all have in common heat welding (creating seamless seams), ponding water-resistant, durability, and more! Roofs Restored offers multiple thickness options: 50mil, 60mil, and 80mil. Each tier comes with an increased energy efficiency, durability, and warranty.