The approach to building envelope design has changed drastically over the last 20 years. Historically, the dynamics of structural loads and bearing have had few adjustments. However, the laws of physics factoring in air/moisture movement and drying through wall assemblies have transformed exterior wall design. As a result, design features in today’s wall system include air barriers, vapor retarders, water resistive barriers and flashing systems to address these performance concerns.
Penetrations through the wall assembly are of the greatest interest and are mission-critical when it comes to integrating these features into wall design. Fenestrations, or windows, are typically the largest penetration through the building envelope. This opening, both by the component’s design and flashing installation, must combine all the features of protection to prevent air movement, moisture and water intrusion.