What defines an air barrier assembly?

An air barrier assembly is defined by the materials that are combined with necessary accessories to create a continuous barrier that restricts air movement across the building envelope. This includes not only the primary materials, such as membranes or sheathing, but also accessories like sealants, tapes, and fasteners that enhance the performance and integrity of the assembly. The integration of these components ensures that the assembly effectively mitigates air leakage, which is critical for energy efficiency, comfort, and moisture control.

While individual materials and accessories play significant roles, it is the comprehensive assembly of these materials in conjunction with the appropriate accessories that provides the functionality of the air barrier. This holistic approach is essential for achieving a continuous and effective air seal throughout the building’s structure. The focus on the assembly rather than isolated components emphasizes the importance of connectivity and installation technique in ensuring the air barrier performs as intended.