Green Building Library
Advanced Air Sealing:
Electrical Boxes
Electrical boxes in outside walls and ceilings should be sealed. Although the leakage through each box might be small, there quite a few of them on the outside walls of the house. There are three options that work for electrical boxes in walls and ceilings:
- Install a gasket behind the face plate. In order to work the gaskets must press firmly against the drywall on all sides.
- Apply sealant between the box and drywall. Also seal the hole where the wire enters the box and any other holes in the box. Your job will be easier if you choose plastic boxes without holes.
- Buy special “airtight” electrical boxes for the outside walls. These have a variety of features to minimize the labor of air sealing. Some are specially made electrical boxes. Others are plastic additions that fit inside or around a typical box.
