Abstract:
While damages due to ponding are common and expensive, provisions for design and
construction of flat roof systems lack guidance regarding these loads. The goal of this research is
to present methods of designing or building flat roofs that are less vulnerable to this condition. An
investigation of the literature, building codes and design specifications has been undertaken. It
was found that although ponding theory has expanded to cover many areas in the literature,
details within design specifications are still lacking. The effect of ponding loads has been studied
through numerical analysis. This investigation confirmed the basic published theory, and also
presents new results. It was found that for a roof close to the ponding stability limit, slope does
not provide large benefits until it is steeper than many commercial roofs. A design of a full-scale,
realistic experiment has been completed. This design calls for loading open web steel joists under
ponding loads to failure. It is hoped that through this test, the contribution of the ponding effect to
the total load can be determined and the results will provide better design and construction
methods for this type of roof system.
