Abstract: Covers for structures, for example drainage channels or the like, which can be installed into a floor are known, said covers comprising a surface (11) which can be accessed and driven over and which comprises a flat structure (13) on a first lower plane and elevations (14) with top surfaces lying above the flat structure (13) on a second higher plane. The aim of the invention is to improve the non-slip properties and to achieve a self-cleaning effect This is achieved in that the top surfaces (15) have an anti-slip surface structure which comprises a plurality of individual elevations. The ratio of the air volume below the individual elevations (16) to the volume of the individual elevations (16) is Vv/Vm=(0.01 to 0.5)/(0.001 to 0.05).

Abstract: A drainage body is disclosed which comprises at least two substantially identically shaped surface units, that is a base unit and a substantially identically shaped top unit, which are combinable with one another in an installation spacing by way of spacers. It is proposed to form the surface units to be substantially interlockingly stackable in such a manner that the installation spacing of the surface units is considerably larger than their spacing in the stacked condition, whereby the spacers essentially have, for example, a frusto-conical or frusto-pyramid shape with a circumscribed cross-sectional area which becomes smaller as its distance from the surface units increases. As an alternative to this, it may be provided that the spacers are disposed in such a manner on the surface units that the base units and the top units are layable so as to be overlapping one another in the manner of a masonry bond. As a result this creates high stability with simultaneous space-saving storability and transportability.