The Oventrop base mat system “Cofloor” with its coordinated components allows a fast laying of the pipes by only one person. The Oventrop base mats NP-35 and NP-11 are a suitable thermal and sound insulation made of expanded polystyrene, thermal conductivity group 040, covered with a polystyrene foil, building material class B 2, which is laid directly onto concrete screed or, if required, onto the additional insulation. The special grid pattern (50 mm between the nodules) is suitable for 14 or 16 mm PEXc pipes “Copex”, PE-RT pipes “Copert” and composition pipes “Copipe”. The handy base mats have practically no wastage. They can be laid economically and easily in any room whether it is small with many angles or with a large surface area. Laying base mats in larger rooms starts in a corner opposite the entrance door. The outer rows of the base mats are connected like a press button closure. At the end of the room the base mats can be cut to size as required. Any off cuts can be used in the same order. By using the polyethylene foil of the edge isolating strip and the overlap of the base mat, the floor surface is completely covered and ready for the concrete or liquid screed to be laid. Therefore a sound bridge to the raw concrete flooring is avoided. Several types of base mats are available with varying thickness of insulation: NP-35, NP-11 and the foil base mat NP-R (without thermal insulation made of polystyrene).