Roof base sheets come in various materials, including bitumen, thermoplastic, and rubber. Bitumen membranes, for instance, are commonly used due to their excellent waterproofing properties and flexibility. They are often applied in a two-layer system, providing redundancy in protection. Thermoplastic membranes, on the other hand, are known for their UV resistance and energy efficiency. They can reflect sunlight, reducing cooling costs in warmer climates. Rubber membranes are also a popular choice, especially in commercial buildings, due to their resilience and ease of installation.