Building Basics
House is Wrapped in Vapor Barrier: Drainage Plane Behind Exterior Wall Cladding
What?
After the roof assembly is completed, a water-resistant barrier should cover the entire house and the seams should be taped to provide a complete drainage system.
Why?
When some moisture gets past the siding, a wall water barrier provides a path for it to safely drain down and away from the wall and gives the home comprehensive moisture protection.
How?
This barrier can be one of the following:
- Housewrap that is lapped shingle-style
- Water-resistant rigid foam insulation that is taped or sealed at all seams
- A wet-applied moisture-resistant coating
- Other water-resistive barrier materials that are recognized by the ICC-ES or another accredited agency.
The water barrier must be thoroughly sealed and flashed at:
- All exterior wall openings and penetrations (e.g., windows, doors, water spigots, exhaust vent outlets, HVAC condensate lines, light fixtures, and receptacles)
- All wall intersections (e.g., roofs, foundations, and other transitions).