Incorrect Method

Photo Source: Summerhill	Photo Source: Summerhill
Photo Source: Summerhill	Photo Source: Summerhill

Sealing Electrical Boxes:

After installation of the polyethylene the boxes must be sealed to it to maintain a continuous barrier to air infiltration. This is most commonly done using acoustical sealant between the layers. It is important to note that these layers must be fastened to one another. The above method has no way to fasten the poly box to the polyethylene sheet. While this may be sealed initially, it will likely not stay that way. Remember that air barriers must be constructed rigid and strong enough to withstand air pressure differences.