Abstract

To study and quantify the effect of effective standoff in standing seam roof systems, a test program of twenty-five roof assemblies was performed with varying clip type, panel type, clip height, and batt insulation thickness; and the results are presented in this paper. The tests measured the overall rotational stiffness of the connection between the purlin and the panel as well as the relative stiffness of the clip-to-purlin and clip-to-panel connections. Utilizing the rotational stiffness data from the tests, the effective standoff of the purlin-to-panel connection is quantified for each standing seam configuration. General trends in the effective standoff are reported and recommendations for approximate effective standoff values for various panel-clip-seam configurations are provided. Additional recommendations for performing tests to determine the effective standoff of a standing seam system are also presented. For most of the test assemblies, effective standoff distance is close by the mid-height of the clip. For a system of floating clip with vertical rib panels, the flexibility in the purlin-clip connection is greater which means the effective standoff distance is reduced, approaching to the top flange of the purlin. On the other hand, for the tests where the seam was uncrimped, the stiffness of the clip-flange connection is reduced, resulting in a shift in the standoff distance towards the top of the clip. It is also observed that the inclusion of fiberglass batt insulation between the clip and the purlin had no perceptible effect on the stiffness of the purlin-clip connection and did not change the effective standoff.