Sheet-like structure with surface protrusions for providing spacing, grip-enhancing, draining elements and the like

A sheet structure in combination with a membrane, said sheet structure being provided with surface protrusions to which said membrane is connected providing a spacing effect for the membrane, the sheet structure comprising an extruded sheet element which has a main base layer and, on at least one face of said main base layer, a plurality of peduncles which are formed monolithically with said main base layer during the extrusion of said sheet structure and which have a solid transverse cross-section and which protrude from said main base layer, said plurality of peduncles having contact coupling surface portions which are spaced distally from said main base layer maximally with respect to non-contact non-coupling surface portions of said plurality of peduncles such that said contact coupling surface portions are arranged more distally from said main base layer than said non-contact non-coupling surface portions, and said membrane having a surface which is arranged in contact with said contact coupling surface portions of said plurality of peduncles and which is coupled with said contact coupling surface portions of said plurality of peduncles for providing said spacing effect for the membrane from the main base layer of the sheet structure.