A floor covering formed by a plurality of panels each having two opposite edges arranged to couple adjacent panels to each other. The coupling parts include a tongue and a groove, as well as locking parts preventing the drifting apart of two such adjacent panels. A separately manufactured insert is provided between at least two of the coupled panels, and the tongue and groove. The insert comprises at least two portions functioning as fixed spacing elements with a first portion between the upper side of the tongue and the lower side of the upper lip, and a second portion between the locking parts.