MiraDRI 860/861 is a self-adhering sheet membrane consisting of rubberized asphalt laminated to polyethylene to form a minimum 60-mil (1.5 mm) membrane. The combination of these two excellent waterproofing materials provides a high-performance, extremely durable waterproofing barrier. MiraDRI 860/861 is suitable for installations where the ambient temperature is 40°F (4.4°C) or above, or in applications between 25°F (-3.9°C) and 40°F (4.4°C) if the product is stored in a heated area until use and the laps are treated with Henry contact adhesive.