Set of building panels comprising a locking device

A set of building panels, comprising a first panel and a second panel and a locking device for locking a first edge portion of the first panel to a second edge portion of the second panel to obtain an assembled state of the first and second panels, wherein a core of the first and second panels comprises a polymer-based material, the locking device comprising:

• a locking element extending upwards from a lower strip provided in the first edge portion, and a locking groove arranged in the second edge portion, the locking groove being open downwards, wherein the locking element and the locking groove are configured to cooperate for horizontal locking of the first and second edge portions, and
• a cavity arranged in the first edge portion and a displaceable protrusion arranged in the second edge portion, the cavity being open horizontally outwards with respect to the first panel, wherein the protrusion and the cavity are configured to cooperate for vertical locking of the first and second edge portions,
• wherein the protrusion extends at least partially upwards and is integrally formed with the second edge portion,
• wherein, in the assembled state, the protrusion extends at least partially horizontally inwardly of a vertical plane with respect to the second panel, said vertical plane extending between upper portions of the first and second edge portions, and
• wherein upper portions of the first and second edge portions comprise a shelf portion and a lap portion, respectively, configured to cooperate with each other at overlapping cooperating surfaces, said cavity extending below the shelf portion,
• the overlapping cooperating surface of the shelf portion being provided in an upper section of the shelf portion, and the overlapping cooperating surface of the lap portion being provided in a lower section of the lap portion.