The present invention relates to a membrane comprising a bulkhead layer, wherein more than 50% by weight of the bulkhead layer is composed of PVC, and a barrier layer. The barrier layer can, on the one hand, be a barrier layer S1, wherein the barrier layer S1 has a polyvinyl alcohol layer comprising more than 50% by weight of copolymer PA, which is connected to the bulkhead layer by a polyurethane layer, wherein more than 10% by weight of the polyurethane layer is composed of polyurethane PUR. The barrier layer can, on the other hand, be a barrier layer S2, wherein the barrier layer S2 has a composition comprising 5-50% by weight of polyurethane PUR and 50-95% by weight of copolymer PA. The membranes according to the invention have significantly lower plasticizer migration compared to the membranes of the prior art and are distinguished by improved resistance to aging, particularly as regards the adherence of the barrier layer on the bulkhead layer, and imperviousness to damp.