_Aluminum wiring in residential homes carries an increased risk of starting a fire when compared with the much more common copper wiring.
The US Consumer Products Safety Commission (US CPSC) investigated this threat in the 1970s and found that many home fires were caused by overheated connections involving aluminum wiring.
The weakness is not with the wire itself, but rather in the wiring junctions and connections between the aluminum wire and things like light fixtures, switches and outlets. While aluminum is an excellent conductor of electricity, it expands and contracts more than copper and is much more prone to corrosion at connection sites; this can cause increased resistance in connections, which, put simply, means more heat that can lead to fire.
Does Your House Have Aluminum Wiring?
During the 60s and early 70s, it was more economical to wire homes with aluminum than copper. As a result, a number of homes during this time period were wired with aluminum, many of which were “tract”-type homes. The US CPSC estimated that approximately two million homes were wired with aluminum between 1965 and 1974.
The best way to determine if your house has aluminum wiring (and the condition of that wiring) is to hire a a professional electrician. They can do things like open your electrical panel, inspect plug and fixture connections, or find and inspect electrical junctions. These types of operations, especially when they involve potentially faulty aluminum wiring connections, carry a risk of electric shock, so they should be approached professionally and with extreme caution.