Wealter moistureproof vapor barrier membrane and waterproof vapor permeable membrane can be applied to double-layer metal roofs, single-layer metal roofs, cold storage floors, curtain walls, steel and wooden structures, mobile homes and other fields, with its unique waterproofing, vapor permeability, airtightness, strength, and weatherability, to achieve systematic waterproofing, moisture and airtightness management for the enclosure structure to maintain the best condition for a long time, so as to make the building energy-saving more durable.