The engineering of air barrier and building envelope details for the construction of exterior walls requires that construction sequence and quality assurance be addressed. Further, the assembly of specific materials should not be based merely on “what was used in the last project” since the interior and exterior conditions of a given building may be vastly different from the proverbial last project.

The word “connectivity” is used in the information technology industry, and this word has been deliberately selected for the title of this paper to describe the inter-connection of materials that form an air barrier system in exterior wall assemblies.

This paper considers the air barrier system, as it relates to moisture management strategies for condensation and precipitation control, exterior and interior conditions, and the quality assurance of the air barrier installation. An example wall assembly is presented to demonstrate some of the issues that must be considered during the construction sequence.