A flooring system comprising floor panels (100, 200) and a connecting system comprising a connecting device for connecting the floor panels, wherein the flooring system comprises: a first floor panel and a second floor panel, and a connecting device comprising a first connecting element and a second connecting element, wherein the first connecting element is configured to cooperate with the first floor panel and the second floor panel for horizontally connecting the first floor panel and the second floor panel, the first connecting element comprising a first locking element configured to engage with a locking groove provided in an underside of the first floor panel and a second locking element configured to engage with a locking groove provided in an underside of the second floor panel, wherein the second connecting element is configured to cooperate with the first connecting element for vertically connecting the first floor panel and the second floor panel, the first connecting element comprising a male connecting element and the second connecting element comprising a female element, or vice versa, the male connecting element being configured to engage with the female connecting element for providing said vertical connection, wherein an edge portion (160, 270) of the first floor panel and the second floor panel comprises a recess (140, 240), the recess of the first and second floor panel being provided below an upper lip (141, 241) and above a lower lip (142, 242) provided in the edge portion, and wherein an expansion portion (326, 327) of the connecting device is configured to be at least partly provided in the recess (140, 240) of the first and/or second floor panel when the first and second connecting elements are cooperating and thereby vertically connecting the first floor panel and the second floor panel, said expansion portion (326, 327) being further configured to expand during connection of the first and second connecting elements, said expansion portion (326, 327) being expanded in a connected state of the connecting device, characterized in that the second connecting element being configured to be spaced from the lower lip (142, 242) of the first and second panels when the first and second panels are vertically connected. a first floor panel and a second floor panel, and a connecting device comprising a first connecting element and a second connecting element, wherein the first connecting element is configured to cooperate with the first floor panel and the second floor panel for horizontally connecting the first floor panel and the second floor panel, the first connecting element comprising a first locking element configured to engage with a locking groove provided in an underside of the first floor panel and a second locking element configured to engage with a locking groove provided in an underside of the second floor panel, wherein the second connecting element is configured to cooperate with the first connecting element for vertically connecting the first floor panel and the second floor panel, the first connecting element comprising a male connecting element and the second connecting element comprising a female element, or vice versa, the male connecting element being configured to engage with the female connecting element for providing said vertical connection, wherein an edge portion (160, 270) of the first floor panel and the second floor panel comprises a recess (140, 240), the recess of the first and second floor panel being provided below an upper lip (141, 241) and above a lower lip (142, 242) provided in the edge portion, and wherein an expansion portion (326, 327) of the connecting device is configured to be at least partly provided in the recess (140, 240) of the first and/or second floor panel when the first and second connecting elements are cooperating and thereby vertically connecting the first floor panel and the second floor panel, said expansion portion (326, 327) being further configured to expand during connection of the first and second connecting elements, said expansion portion (326, 327) being expanded in a connected state of the connecting device, characterized in that the second connecting element being configured to be spaced from the lower lip (142, 242) of the first and second panels when the first and second panels are vertically connected.