• If panel-type air barrier material is used, all joints must be sealed to prevent air leakage

• If flexible sheet material is used, all joints must be:
  • Sealed, or
  • Lapped not less than 4" (100mm) and clamped (between framing members, furring, blocking and rigid panels)

9.25.3.3.(1) Where the air barrier system consists of an air-impermeable panel-type material, all joints shall be sealed to prevent air leakage.

9.25.3.3.(2) Except as provided in sentence 9.25.6 (3) where the air barrier system consists of flexible sheet material, all joints shall be

a) sealed, or

b) lapped not less than 100 mm (4") and clamped, such as between framing members, furring or blocking and rigid panels.