Did You Know: Some Older Homes Were Wired With Aluminum
If your house went up in the mid-1960s to late 1970s, this is worth knowing about.
Aluminum wiring is not a reason to panic. It is a reason to know what you have.
Summary
- Aluminum branch wiring was used widely in homes built from roughly 1965 to 1975.
- The wire itself is not the issue; the connections are.
- There are accepted repair methods short of rewiring the house.
Key Takeaways
- Aluminum branch wiring is a known issue, not a rumour.
- It is usually identifiable without opening walls.
- It can affect insurance and home sales, so it is better known than discovered.
During a stretch of the mid-1960s through the mid-1970s, copper prices pushed many builders toward aluminum for branch circuit wiring, the wiring that runs to your outlets and switches. A great many homes from that era have it. If your home is from that period, it is worth finding out.
The wire is not the problem
Aluminum conducts electricity perfectly well. Large aluminum conductors are still used today for service entrances and feeders, routinely and safely.
The issue with the older branch wiring is what happens at the ends. Aluminum expands and contracts more than copper as it heats and cools, which over many cycles can work a connection loose. It also oxidises differently, and that oxide layer adds resistance. Loose connection plus added resistance produces heat at that point, and that is the mechanism behind the concern.
On top of that, the devices of the era, the outlets and switches themselves, were not designed with aluminum in mind. Pairing the two made the connection problem worse.
How to tell what you have
Often it can be identified at the panel or at a receptacle without opening up walls, and sometimes the cable sheathing is marked. An electrician can usually tell you fairly quickly. That is the right first step, because plenty of people assume they have it based on the age of the house and turn out not to.
What gets done about it
Full rewiring is the most thorough answer and the most expensive, and it is not the only accepted one. There are recognised repair methods that address the connections specifically rather than replacing all the wire, and there are devices rated for use with aluminum. Which approach fits depends on what is actually found.
What is not an answer is a homeowner swapping outlets. Using devices not rated for aluminum on aluminum wiring makes the original problem worse, and it is a common well-intentioned mistake.
Why it is better to know
Aluminum branch wiring can come up with insurers and will almost certainly come up in a home inspection when you sell. Finding out on your own schedule is considerably better than finding out during a contract.
Need this done right?
Jarrett Page has 30 years in the trade and works Dallas-Fort Worth personally.
