A waterproofing system including a functional layer S1 including 10-80 wt.-% of at least one thermoplastic polymer P1 and 10-80 wt.-% of at least one solid particulate filler F, wherein the surface of the functional layer S1 has an Auto-correlation length of waviness W(Sal) of at least 50 μm. Further, a method for producing a waterproofing system and to the use of a mechanical surface treatment step to increase the waviness factor, determined as the ratio of the Root mean square roughness of waviness W(Sq) to the square of the Auto-correlation length of waviness W(Sal), of a surface of a functional layer S1.