Vapor barriers and air seals are used to keep exterior walls and the foundation of a structure dry from moisture and free of air leaks. While both are critical in prolonging the lifetime of your home or structure, they often require added attention in installation. 

Vapor Barrier installation guidelines:

1. 6 mil minimum in zone 7.
2. Membrain or Foil-Scrim-Kraft paper at concrete.
3. Cut vapor barrier in ways to minimize seams.
4. Overlap all seams by 16″-24″. Remove excess overlap.
5. Make sure to have 100% coverage of exterior wall surfaces including stud pack and headers.
6. Tape all seams.
7. Tape all outside corners.
8. Tuck inside corners.
9. Tape roof to exterior wall seam.
10. Tape bottom plate termination.
11. Tape seal to electrical receptacles.
12. Tape seal miscellaneous mechanical, electrical, and plumbing penetrations.
13. Tape seal to rough opening framing.

Air seal install guidelines:

1. Sealant to stud packs.
2. Sealant around window headers.
3. Foam plate penetrations.
4. Foam window/door rough opening.
5. Seal studs, plates, rim joists, box sills, and heel cuts at intersections with exterior sheathing.
6. Caulk plate to subfloor.
7. Seal sheathing seams.
8. Putty pad (1/8″ pliable self stick pad) electrical receptacles in exterior walls.

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Vapor Barrier