Spandrel Panel.
The opaque infill panel in a curtain wall that conceals the floor slab and edge zone.
A spandrel panel is the opaque (non-vision) infill panel in a curtain wall, typically positioned at floor-slab level. It conceals the structural slab edge, perimeter beams, raised access floor zone and ceiling void from external view, and provides the thermal and fire-rated separation between floors.
A typical spandrel build-up consists of an outer toughened glass or metal cassette face, a ventilated cavity, A2-rated mineral wool insulation, and an insulated back-pan sealed to the curtain wall frame. On relevant buildings under Approved Document B, all materials in the spandrel must achieve European Class A2-s1,d0 or better.
Spandrel panels often incorporate the cavity barrier and fire stop that maintains the compartment line between floors, making them a critical fire safety element of the facade.