There are several different types of waterproofing membranes available, including: 1. Liquid applied membranes: These are liquid-based coatings that can be applied to various surfaces, such as concrete, metal, or wood. They form a seamless and flexible barrier that prevents water penetration. 2. Sheet membranes: These are preformed sheets made of materials like bitumen, PVC, or EPDM rubber. They are often used in below-grade applications, such as foundations or basements, as well as on roofs. 3. Self-adhered membranes: These membranes have a sticky backing that allows them to be easily applied to a surface. They are commonly used in roofing applications, as well as in below-grade waterproofing. 4. Cementitious membranes: These are cement-based coatings that can be applied to concrete surfaces. They are highly durable and resistant to chemicals and water, making them suitable for applications like swimming pools or tanks. 5. Bentonite membranes: These membranes are made of bentonite clay, which swells when it comes into contact with water, creating a watertight seal. They are often used in below-grade applications or as a supplement to other waterproofing systems. 6. Rubberized asphalt membranes: These membranes are made from a combination of rubber and asphalt. They are usually applied using heat, which melts the asphalt and allows it to adhere to the surface. They are commonly used in roofing applications. 7. Synthetic membranes: These membranes are made from synthetic materials like polyvinyl chloride (PVC), ethylene propylene diene monomer (EPDM), or chlorinated polyethylene (CPE). They are highly flexible and can be used in a variety of applications, including roofs, foundations, and below-grade waterproofing. Each type of waterproofing membrane has its own advantages and is suited to different applications. The choice of membrane depends on factors such as the specific waterproofing needs, the substrate, the environmental conditions, and the budget.