An extended method for comparing watertightness tests for facades

Watertightness tests for building facades attempt to simulate the most relevant climatic exposures for water penetration by reproducing standard conditions. Such conditions do not represent all possible climatic exposures, hence a new method was recently presented that relates test severity to watertightness performance of a facade under any operating conditions. In addition, test conditions vary for each regulatory framework (i.e.the results generated for one test cannot necessarily be extrapolated to other tests). A process is presented for considering the influence of exposure time. This allows a comparison of the severity of the conditions imposed by different watertightness tests independently of the exposure parameters. This comparison, which is based on a performance criterion, can enable a global certification of watertightness of any facade design under any operating conditions using results from only one watertightness test. The method developed herein was applied to facades under various operational conditions at a reference location, comparatively evaluating the conditions recreated by different international watertightness tests. The results suggest that American tests are more appropriate for recreating high climatic exposures, while European tests are more suitable for evaluating moderate and protected conditions of wind-driven rain and wind pressure.