9.25.3 Air Barrier Systems

  • Assemblies separating the indoor air from the outdoor air must be constructed with an air barrier that will provide a continuous barrier to air leakage:
    • From the inside into the assemblies enough to prevent excessive moisture condensation
    • From the exterior or the ground inwards, enough to:
      • Prevent moisture condensation on the room side
      • Ensure comfortable conditions for the occupants
      • Minimize the ingress of soil gas