GB/T 328.10-2007 "Test methods for building waterproof sheets — Part 10: Bitumen, plastic and rubber sheets — Water impermeability" specifies the test conditions, procedures, and evaluation criteria for the water impermeability performance of two types of waterproof sheets, serving as a core reference for material selection and quality inspection in waterproof engineering. The test requires the use of a waterproof sheet impermeability tester (hydrostatic pressure resistance tester), equipped with a precise pressure control system and a transparent observation window. Under an ambient temperature of (23±2)℃, the specimen is sealed and clamped, subjected to the specified water pressure, and held under pressure. Water leakage is monitored through the observation window to evaluate the sheet's resistance to water penetration, ensuring the effectiveness of building waterproofing.