Designing structures resistant to tsunami-like flood flow impacts is contingent on the ability to accurately predict dynamic loading effects on building components. To characterize these effects, two metal building cladding subassembly test specimens, designed for Risk Category II and Category IV wind loading, were experimentally subjected to surges and bores with various wave height and initial water levels. The results reveal that maximum structural responses, quantified by curvatures and displacements, occur after initial wave impact, as splash up on the structure subsides. Furthermore, consistent pressure-time histories between specimens in equivalent flow conditions, despite significantly different strains and displacements, suggest structural flexibility does not influence which wave forcing produces the maximum structural response. Lastly, structural analysis of the specimens, based on measured pressures at maximum strain conditions, reveals that loading conditions ranged between hydrostatic and hydrodynamic depending on the initial flooding conditions. With these findings, a method to predict pressure magnitude and distribution on the cladding at the time of maximum structural response for tsunami-like flood flow impacts is proposed. (c) 2020 American Society of Civil Engineers.