Windborne debris and the building envelope

Twenty-three years of documented windstorm damage experiences illustrate the importance of protecting the building envelope from windborne debris and fluctuating pressures that occur during windstorm events. A 2 × 4 timber and roof gravel are defined as representative objects for use in standard tests to qualify products for use in the building envelope. A 9000 cycle pressure spectrum that represents fluctuating pressures which occur in a hurricane is also specified for product qualification tests. The evolution of these test standards is traced and building codes that have adopted these criteria are referenced. Current design practices that are responsive to these windstorm effects and standard tests are described. Windows and architectural glazing systems that can protect openings in the building envelope from being breached by windborne debris are illustrated.