Recently, waterproofing systems made of PVC membranes, used in the construction of high-rise buildings with a developed underground part, have gained great popularity. Due to the considerable depth and magnitude of static loads at the foundation level, the complete replacement of such waterproofing with standard methods in case of its damage is practically impossible. To avoid this situation, a multi-layer PVC waterproofing membrane system with a geotextile middle layer was created. To repair such a system it is supposed to inject a polymer composition into it through special tubes, which after curing restores the waterproofness of the membranes. The article presents the results of an experimental assessment of the maintainability of the described waterproofing system. It was proved that the injection of the repair composition into the middle geotextile layer is possible even with external static pressure on the membranes of 146 t/m2. At the same time, the high resistance of PVC membranes to the long-term action of a significant static load and repair composition was found, and the durability of a waterproofing system, predicted from the point of the thermal-fluctuation theory of the destruction of solids, under operating conditions for shear was about 50 years.