One-component, polyurethane-bituminous, liquid waterproofing membrane. Suitable for waterproofing of underground structures (e.g. foundations) and green roofs. Also suitable for under-tile waterproofing of kitchens, bathrooms, balconies, flat roofs and terraces with prior quartz sand broadcasting on its last layer. Forms an elastic membrane, without seams or joints. Has excellent adhesion to various substrates, such as concrete, cement screeds, bituminous coatings, etc.