Anchoring of connector element

A method of anchoring a connector element in a receiving object, the receiving object being a lightweight building element comprising a first building layer, and an interlining layer distally of the first building layer, wherein the first building layer is thinner and has a higher density than the interlining layer, and wherein the receiving object is provided with a mounting hole for receiving the connector element, the mounting hole penetrating the first building layer and extending into or through the interlining layer, and the connector element having a distal end and a proximal end, the method comprising the steps of:

• inserting the distal end of the connector element into the mounting hole in an insertion direction along an insertion axis;
• inserting a sleeve comprising a thermoplastic material into the mounting hole, the sleeve enclosing the connector element;
• causing a distally facing liquefaction face of the sleeve to be in contact with a proximally facing support face of the connector element;
• transferring energy to liquefy at least a flow portion of the thermoplastic material of the sleeve and pressing the liquefaction face against the support face to cause at least a fraction of the flow portion to flow radially outward;
• and
• causing the flow portion to re-solidify, whereby the re-solidified flow portion anchors the connector element in the receiving object.