The end of a beam is joined to a wall structure by a self-releasing structural assembly. The self-releasing structural assembly has a first portion that is anchored to the wall. A second portion sticks out from the wall. This portion is fireproof and non-thermally degradable. It defines a seat for receiving the beam end. The assembly also includes a thermally degradable member mounted to the second portion. In normal use the beam fasteners squeeze the end of the beam, the support bracket seat, and the consumable, thermally degradable member in compression. When exposed to heat or flame the consumable, thermally degradable member softens, releasing the compression in the structural sandwich of parts. The end of the beam is then able to translate away from the wall structure. The consumable member can be inspected, replaced if necessary, and the beam fasteners re-tensioned, without removing the beam end from the seat.