Building components and cladding: recent developments and future possibilities for assessing of wind effects

Prof. Greg Kopp of the University of Western Ontario

Post-storm investigations indicate that the vast majority of wind damage is due to failures of the building envelope. Determining the wind loads on small components such as multi-layer, air permeable cladding is extremely difficult for standard tools like boundary layer wind tunnels, which were originally developed to determine structural loads on high-rise buildings. In fact, one may question whether it is even possible to use such test methods to obtain wind loads for design of certain types of components or cladding. As a result, several large-scale and full-scale labs have arisen from the need to address these issues. These labs are now being used to assess both the wind loads and the component performance, often under identical conditions. One significant benefit is that these labs also offer insight into the fundamental mechanisms involved, allowing us to change the way we conduct and interpret the more traditional tests.  This may allow one to define more precisely the criteria with which to use small-scale wind tunnel models for defining wind loads on small components, or to improve standardized (i.e., simple and inexpensive) product tests that capture performance reliably.