What is aluminum wiring?

Aluminum wiring consists of aluminum conductors used in branch circuits (the smaller wiring that distributes power to outlets, switches, and light fixtures throughout a home) rather than the copper wiring standard in most residential electrical systems. It became common in homes built during the 1960s and 1970s when copper prices rose, particularly in the Southeast including Spartanburg.

You can identify aluminum wiring by its silvery-gray color when the insulation is removed, or by checking the wire itself if accessible in attics or walls. It may be labeled "AL" or "aluminum" on the sheath. Aluminum wire is slightly thicker than copper wire of the same amperage capacity.

Aluminum wiring creates distinct problems that copper does not. The metal oxidizes when exposed to air, forming a corrosive layer that increases electrical resistance at connections. This oxidation causes connections to loosen over time, heat buildup at outlets and switches, and potential fire hazards. The wire also expands and contracts more than copper with temperature changes, further loosening connections. These issues mean aluminum-wired homes cannot be treated the same as copper-wired ones. Connections require special anti-oxidant compound and different techniques than standard practice. When buying or maintaining a Spartanburg home with aluminum wiring, having a qualified residential electrician evaluate the system is important to ensure safe operation.