Testing and modeling of hurricane wind-driven rain water ingress, propagation, and subsequent interior damage in residential buildings

Abstract

Hurricanes are a main cause of economic losses in the world, including Florida. They affect exterior, interior, and the contents of residential buildings. The interior damage can be as much as half of the cost of total damage, but the estimation of the interior damage is still somewhat crude. Most damage models estimate interior damage as a percentage of the exterior damage, or through simple relationships, that relate the height of water ingress in the building to the interior damage. This paper presents a new model for interior and contents damage estimations, which takes into account the physical mechanisms of hurricane-induced interior and contents damage from rainwater ingress. The method incorporates the results of large and full-scale tests to quantify the rainwater propagation and distribution from component to component in the interior of the building, and combines the test results with estimates of water resistance characteristics of the building interior and contents, and with cost analyses. The model is part of the commercial residential low-rise vulnerability model of the Florida Public Hurricane Loss Model (FPHLM). The paper presents the impact of the model on the FPHLM vulnerability curves, and illustrates how the new model can help evaluate mitigation strategies.