Photo Source: Summerhill

9.36.2.9. 2) An air barrier system installed to meet the requirements of Sentence (1) shall be continuous

a) across construction, control and expansion joints,

b) across junctions between different building materials and assemblies, and

c) around penetrations through all building assemblies.

9.36.2.9. 6) Where the airtight material used in the air barrier system is installed toward the exterior of the building envelope, its location and properties shall conform to Subsection 9.25.5.

A-9.36.2.9.6) Exterior Air Barrier Design Considerations . Any airtight assembly - whether interior or exterior - will control air leakage for the purpose of energy efficiency. However, the materials selected and their location in the assembly can have a significant impact on their effectiveness with regard to moisture control and the resistance to deterioration of the entire building envelope.