Does taping the joints between sheathing or insulation board make an air barrier?
Since most sheathing itself is an air barrier, taping the joints makes a continuous wall air barrier. However, unlike CCW-705 self-adhering or Barriseal fluid-applied membranes, which fully cover the wall, tape has many exposed edges where cycles of heat, cold and moisture will work the bond loose over time. Also, workmanship in taping the joints is critical as any wrinkle or fishmouth would present a breach in the system. Then, there is still a requirement to tie the wall air barrier to the roof and foundation. CCW Window & Door Flashing over primed surface makes an effective air barrier sheathing tape. However, the CCW-705 or Barriseal full coverage membrane air barriers provide superior durability and continuity.
