In this paper, a first-order design sensitivity analysis is presented for dynamics responses of roof sheeting under hailstone impacts. The presented design sensitivity analysis computes the rate of various response changes with respect to the relevant design variable for roof sheeting. For this purpose, exploiting the finite element method, the dependence of response measures, such as deflection, stress and strain on the thickness and material properties of the steel sheeting, is implicitly defined. Then the minimum required thickness for each steel grade under different loading conditions for sheeting, are suggested by considering two conditions according to the hailstones sizes: no damage (yielding) for hailstones of small sizes (20 mm or less) and no penetration (failure) for hailstones of large sizes (up to 100 mm). © The Society for Experimental Mechanics, Inc. 2013.