Wind-Driven Rain as a Design Parameter

This paper will show: 1 Given the significant contribution of WDR to building damage and the fact that other environmental loads are already considered by engineers involved in building envelope design, consideration of WDR by the engineer may be a reasonable expectation. 2 The use of WDR as a design parameter could help in the construction of buildings that have greater resistance to water intrusion and long-term deterioration from exposure to moisture. The computed pressures and associated WDR values could help designers select appropriately rated window and wall systems. 3 WDR intensity on the various elevations of a building can be reasonably approximated using publicly available weather data and the semi-empirical methodology presented herein. 4 AS shown by examples of WDR and pressure calculations for 4 California cities, WDR intensity varies considerably by location and by building elevation. This fact could lead to the development of WDR index maps similar to those generated for freeze-thaw or for wind and snow loads. 5 Based on limitations of the currently available weather data, the methodology presented herein is appropriate for providing relative assessments of WDR exposures between various geographic areas and building elevations.