Thermally charged wall structure and method to seal gaps in such a structure

The thermically-loaded wall (2), acted on by a hot gas (17), has 2 directly adjacent wall segments (33,35) separated by a gap (55) which is sealed by the thermic expansion of a flexure element (45) attached to one wall segment (33), cooperating with a pressure surface (49) attached to the other wall segment. Flexure element has a hot surface (53) and a cold surface (51) on its opposite sides, for providing an uneven thermal expansion causing it to flex into engagement with the pressure surface.