Wind Effects on Metal Edge Flashings

This thesis presents the full-scale measurements of wind pressures on four different metal edge flashing profiles installed on the Texas Tech University Wind Engineering Research Field Laboratory (WERFL) test building at different wind angles of attack (windward, leeward, quartering and parallel direction). The distributions of wind pressure coefficients (Cp) on each flashing are plotted and discussed. Using the measured wind pressure coefficients (Cp) and influence coefficients (IC) obtained from a Finite Element Analysis, the combined wind effect coefficients (GC) for each flashing were developed. A general equation similar to that in ASCE 7-93 is introduced to determine the wind effects (fastener pullout force, deflection and maximum stress) on metal edge flashings. From the study, it is clear that pressure distributions on metal edge flashings strongly depend on size and profile shape of the flashings, location on the building and angle of attack of the wind. The largest mean pressure coefficients occur when the wind is blowing normal to the wall. However, near a roof comer, the most critical wind direction is a quartering wind. Substantially large mean pressures occur on both the horizontal and vertical flanges of the flashings near sharp comers. These pressures are not predicted by current codes and standards.