Photo Source: Summerhill

Installing the vapour retarder and/or air barrier:

When fastening the polyethylene, it is important to start at corners to make sure they are securely fastened on both sides of the corner. When using this method the polyethylene cannot be pulled out. This prevents the creation of a rounded corner which will normally get cut by the drywall installers to aid in installation of the drywall panels. Work from one side of the wall straight to the other, this avoids folds in the polyethylene.