During the mid-1960s to the mid-1970s, copper was expensive and some homes were wired with solid aluminum branch circuits. It is still in many homes, and it needs to be handled properly.
Why is aluminum wiring a problem?
Aluminum expands and contracts more than copper, oxidizes, and can creep under screws. At outlets, switches and splices that were made for copper, connections can loosen and overheat. The CPSC has published guidance on the fire risk at those connections.
This is about small solid aluminum branch-circuit wire (15- and 20-amp circuits). Large stranded aluminum service and feeder cable is common, normal and made from different alloys.
What are signs of aluminum wiring problems?
- Warm outlet or switch covers, or a hot-plastic smell.
- Flickering lights or outlets that work intermittently.
- "AL" or "ALUMINUM" printed on cable jackets in the attic or garage.
How is aluminum wiring fixed?
- Rewire with copper: the most complete fix, often impractical for the whole house.
- COPALUM crimp connectors: a special crimp that joins a short copper pigtail to the aluminum wire. The CPSC has recognized it as a permanent repair. It needs special tooling and trained installers.
- AlumiConn connectors: a listed lug-type connector for joining copper pigtails to aluminum, also cited by the CPSC as a repair method.
"CO/ALR" outlets and switches and ordinary twist-on wire connectors are not considered a complete fix by the CPSC. Remediation must be done at every connection point, by a licensed electrician; this is not a DIY job.
IES quotes aluminum wiring remediation from photos or a free estimate.
About these prices: rough starting-at prices from the IES price book. The final price depends on what we find on site, your utility and your city or county. Estimates are free.
Common questions
Is aluminum wiring safe?
Solid aluminum branch wiring from the 1960s and 70s has a documented fire risk at connections. With proper remediation (COPALUM or AlumiConn pigtails) or rewiring, the risk is greatly reduced.
What is the best fix for aluminum wiring?
Rewiring with copper is the most complete fix. The CPSC recognizes COPALUM crimp connectors and AlumiConn connectors as repair methods for pigtailing copper to the aluminum.
General information for California homes under the California Electrical Code (based on the NEC). Local rules and inspectors can vary. Not a substitute for an on-site inspection. Never work inside a panel, at the meter or on live circuits.