deformation resistance of the insulating layer 8 by the factor 50 to 60 accordingly a load acting upon the upper floor layer 2 is practically completely received by the support blocks 9 the insulating layer 8 does not have to carry any load thus it is possible to dimension the insulating layer 8 exclusively in consideration of the insulating effect the load carrying capacity plays practically no role accordingly the insulating layer 8 can be made relatively soft and with a high share of air so that its insulating effect is optimised the insulating layer can also be made thinner to keep the total thickness of the floor plate small the lower floor layer 3 has several transversal supports 10 11 which are formed by a stiffening profile 12 of the lower floor layer 3 this means that the lower floor layer 3 is bent into a wave like shape each support block 9 rests on a transversal support 10 which again rests on a longitudinal support 22 each stiffening profile 12 has two elevations 13 14 and between these a depression 15 thus the stiffening profile 12 forms the transversal supports 10 11 for example of profiled sheet metal the profile being bowl shaped and open upwards this gives a height advantage in comparison with i supports or c supports the depression 15 has a bottom 16 which is placed lower than a main plane 17 of the lower floor layer 3 accordingly the bottom 16 of the depression 15 projects about 60 to 100 mm downwards.