AL About Aluminum wiring
Commonly used throughout the 1960’s and 1970’s, aluminum wiring was yet another alternative during a time when copper wiring prices had drastically increased due to the war waging on in Vietnam. Aluminum was readily available to use at a cheaper cost and didn’t differ too much as far as functionality goes. Because we know things always go according to plan when the cheaper option takes a front seat in the home building process…
To many people’s surprise… Aluminum came with its own unique set of problems.
What exactly were these problems? Im glad you asked!
To conduct electricity means there will be a production of heat, sometimes, a great deal of it. Aluminum in particular can handle heat buildup, but at the cost of something called “Thermal Expansion”. This is a process of the wiring growing/lengthening as it heats and shrinking/shortening as it cools, you can view this short video on thermal expansion to see what we are talking about.
In the context of wiring, we refer to this as “creep” when the wires are moving from their connection. This proved to be an issue because these aluminum wires would become loosened from their connections, which could result in arching of the electricity passing through.
Oxidation was the other common problem. Now, I know what you're thinking - Doesn’t copper also oxidize? I mean look at the Statue of Liberty!
Yes, its does.
However, when copper oxidizes it still remains a suitable conductive material for electricity. Aluminum does not share that same characteristic. In fact, when aluminum oxidizes it actually has increased “resistance” and becomes quite poor at conducting electricity and would often lead to the buildup of heat due to electricity having nowhere to go. Picture what would happen to a balloon on the end of garden hose:
Water wants to move out from the end of the hose (electricity),
That balloon is stopping it from doing so (resistance),
Water begins to build up in the balloon (heat building) until,
it POPS (yea..)
As it turned out, cheaper didn't necessarily mean better.
How do we look at this from an inspectors point of view?
Aluminum may be considered relatively out dated, but under some circumstances can still be present and functioning within a home.
It is always important to discuss with your insurer about their coverage of aluminum wiring within the home. Due to aluminum’s history, some insurers may implement premiums to receive coverage. In other circumstances, if disaster strikes and the presence of aluminum wiring is discovered, it may be possible that insurance becomes voided entirely.
This information isn’t meant to be intimidating, although I know if can be regardless. It all starts with an inspection to help determine whether aluminum wiring is present, appears to be working properly or may even need further review by an electrician. Aluminum wiring doesn’t have to be a stressor in the home. This information and the resources mentioned can help create options and plan a cost effective way to work with aluminum wiring. There are always solutions that can work for you!
We hope you were able to learn something from this Inspection Insight.
As always, if any questions you had about aluminum wiring were not answered here or you have questions about a different topic, please reach out using the contact information below.