Airtight Electrical Box
An electrical box designed to self-seal to your moisture barriers.
Conventional electrical boxes don’t do much to prevent the movement of air through wall and framing cavities. This air leakage wastes energy, leads to comfort complaints, and creates condensing surfaces where mold and rot can get a foothold. Many versions of airtight electrical boxes designed to control air leakage are notoriously finicky and slow to install. However, the new FastCap Air Tight Box is the most promising way to control air leakage through electrical devices that I’ve seen. Employing an adhesive flange that adheres to both polyethylene and smart vapor-retarder air barriers (such as CertainTeed’s MemBrain), the box has rubber grommets that seal around the wires and built-in square-drive screws for fastening. Currently, it’s available only in 24-cu.-in. single-gang sizes, but the manufacturer promises that multiple-gang and fan-rated boxes are coming soon. The box sells for $3 each or $142 for 50.