Abstract: A clip is used to fasten a wall panel to a frame rail. The clip is fitted to the rail and has paul-like tabs which locate in apertures in a side wall of the rail. Corresponding apertures are provided on the edge of the wall. When the edge of the wall is inserted into the clip, the pawl-like tabs snap-fit through the apertures and into the apertures, thereby captively retaining the wall to the rail. Alternatively, the clip may be formed integrally with a rail by pressing out a flap from a side wall of the rail. Each flap has a pawl-like indent. Corresponding apertures are provided on the edge of a wall sheet. When the edge of the wall sheet is inserted between the flaps and the rail, the pawl-like indents locate in the apertures, thereby captively retaining the wall sheets to the rail.