Solid aluminum branch circuit wiring was used in homes from roughly 1965 to 1973 and the Consumer Product Safety Commission has identified it as a fire hazard. The problem is at the connections rather than in the wire – aluminum expands, contracts and oxidizes, and terminations loosen and overheat. The accepted repairs are COPALUM crimps or AlumiConn connectors at every device. Pigtailing with ordinary wire nuts is not an approved fix and is still commonly sold as one.

This is most common in homes built roughly 1940 to 1980. Post-war and mid-century — copper supply, aging cast iron stacks, 60 to 100 amp panels, first-generation central air.

Related

• Federal Pacific or Zinsco panel
• Two-prong outlets throughout the house
• Cloth-covered cable visible in the attic or basement
• Fuse panel, or a 60 amp service
• Fuse larger than the wire it protects
• Ceiling fan mounted to a standard light box
• Knob-and-tube still energised
• No GFCI protection anywhere in the house

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Written by Jaylan Jones. I Like To Fix earns a referral fee when a call connects to a contractor. See our business-model disclosure.