The invention concerns a system for removably securing slats (1) juxtaposed to form a deck, for example for a terrace, comprising fasteners (3) disposed in rows on level floor or joist or beam structure supports (20) oriented perpendicular to the axis of said slats (1), said fasteners (3) comprising means for securing same to the slats (1). This system is characterised in that it comprises a plurality of impermeable channels (2) disposed parallel for a level floor, or at a rate of one impermeable channel (2) for each joist or beam support (20) and thereby covering the top surface of said support (20), removable securing means and positioning means being provided on the profiled section (2) and on the fasteners (3) consisting of a flexible elastic material, said positioning means allowing clearance in the direction of the axis of the channel (2).