Thursday, September 18, 2008

Aluminum Wiring?

It has been my experience as a home inspector for a client to call thinking they have aluminum wiring in their house and after further evaluation it is either proper aluminum wiring or copper wires that appear to be aluminum. A professional home inspector can evaluate the difference if the wire is visible at the time of the inspection.
Here is an example of a common question I have received:

The Client Wrote:
I recently purchased a mid-1940's home that has lots of charm and was well kept. It remains in excellent condition. After reading the Home Inspector’s report, I had some concern about the part that stated the presence of aluminum wiring. In addition, I was also informed that the wiring although appearing to be in good serviceable condition was not up to today’s standards, because it has “no grounds”. The Home Inspector also recommended that a licensed electrician evaluate the electric in the house. I know the house is old, but how much of a danger is this? Do I need an electrician? Is aluminum wiring a problem?
My Reply:

Based on what you told me, I don’t think you have aluminum wiring. Aluminum wiring did not come on the market until the early sixties, and when it did it was all three-wire (the third wire was a ground). Since you do not have a grounded system, I think what you have is two-wire rag romex. This wire is copper coated in nickel. When the inspector looked in the panel he saw the shiny ends of the wire and mistook them for aluminum. The best way of telling the difference is to look for the ground wire, or look at the romex cover. If the cover looks like cloth than it is the old romex. Aluminum wiring is only found with plastic covering.

All aluminum wiring is not bad, only the single strand aluminum found in the lighting and outlet circuits. This single-strand aluminum would get hot and shrink, then get hotter and would cause a fire. However, almost all modern houses use large stranded aluminum wires for service entrance cables and major appliance circuits. The large wires have many strands of wire and have a zero failure history.

Now about the two-wire system you have: although it’s adequate it does not offer the protection that the three-wire/grounded system offers. You do not have a big problem, but to be on the safe side have an electrician look at your system. He can install ground fault receptacles in the most used receptacles, such as the outside receptacles, and receptacles near sinks, this will make that two wire system safe. This is not very expensive and not very time consuming.
It is better to be safe than sorry.

No comments: