m2 Moisture cutting, by means of the drainage system with a 20 mm thick high-density polyethylene (HDPE) drainage layer and compressive strength >200 kPa type DRENTEX PROTECT MAXI, application of a two-layer waterproofing membrane adhered to the poor concrete layer and projected so that it adheres to the foundation slab, formed by double sheet of SBS elastomeric bitumen; the first layer of 3 kg with polyester felt reinforcement (FP) MORTERPLAS SBS FM 3 KG (LBM-30-FP according to UNE 104410) and second layer completely adhered to the lower layer of 4.8 kg, with polyester felt reinforcement (FP) and with a top finish in polyester non-woven fabric type MORTERPLAS PARKING (LBM-48-FP according to UNE 104410) placed after priming with EMUFAL PRIMER with a minimum endowment of 300 g/m2 applied in two or three layers, ready to receive concreting.