Cap sheets are often made from various materials, including modified bitumen, thermoplastic, and traditional asphalt. Modified bitumen is particularly popular due to its flexibility and resistance to UV rays, making it suitable for a range of climates. Thermoplastic sheets, such as PVC and TPO, offer excellent energy efficiency and are known for their durability. Each type of cap sheet comes with its own set of advantages, allowing manufacturers to choose based on specific project requirements and environmental considerations.