How to verify aluminum wiring

Any suggestions on how to verify aluminum wiring versus plated copper wire?? This house is from 1940 and has had remodel after remodel after remodel and all done wrong.

That would be cloth(EDIT: covered tinned copper). Aluminum, by itself, has a thermo PLASTIC covering.


i believe LK has a case of dyslexia
that’s prolly cloth covered tinned copper


Thank you BK!

Yes it is cloth covered tinned copper.

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I agree that the old looking conductors are not aluminum due to the insulation type which is actually rubber covered in a cloth wrapping.

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Morning, Cory.
Hope this post finds you well.

I remember being where you are currently. As a home inspector growing experience.
I learned significantly from INSPECTAPEDIA. Old Electrical Wiring Types, History of Electrical Wire Types Hope you do as well.

May I add. Use the term SUSPECT: ‘an idea or impression,’ when you are hesitant of the exact material followed up by a Recommendation or Referral by a Licensed Trades Contractor, in this case a Licensed Electrical Contractor, for further review and serving.

Good luck.

Robert that’s great info thanks so much!!

I agree it’s better to defer to someone else when you do not know the answer but IMO a HI should be able to differentiate between aluminum and rubber insulated tin coated copper conductors and not have to recommend a licensed electrician merely for the identification.

Would this identification be part of a standard SOP for home inspectors?

Yes, because we have to defer to paper work showing corrective action took place and or an electrician when possible dangerous AL wiring is present, how else? :slight_smile:

You kind of lost me. If this is part of the SOP and what the HI sees is in the photo in the OP why would any recommendation for further evaluation be needed?

Robert, I did not lose you :slight_smile: I meant to say the HI should know the difference between a solid AL and tinned copper wire. If it’s the latter, like in the OP’s pics, then it should not be deferred for further evaluation unless something else is wrong with it, like the rubberized insulation is brittle and falling off all over the place.

I have observed [Tinned Copper](http://Tinned Copper Electrical Wire Identification) cables on several occasions.

How can he/she, the HI know the difference without being destructive?
SOP: III. The inspector is not required to: 1. dismantle, open or uncover any system or component.
I use to remove dead fronts. No more.

Did you read the thread?

Got it, the insulation in the photo looks OK. :slightly_smiling_face:

Yes, the insulation in the OP’s pic “appears” alright. From HI’s prospective, however, it is prudent to point out to the client that the “very old” rubberized insulation eventually dries out and becomes brittle… I have worked on old clothed wiring on several occasions in old buildings in Brooklyn, NY and although at first glance it would appear okay… when you moved the wire by bending or straightening it the rubberized insulation would flake off the wire. Just saying :slight_smile: Old is old, nothing lasts forever. My point, however, in my initial reply was to only point out that a HI should be able to identify what is AL wire and what is tinned copper wire, nothing more.

That’s your business… where I reside, we’re required to remove the panel’s cover.

If your training included information when aluminum wiring was used. and you know the age of the house you could answer this question yourself.( what else did your training not include?)

Not trying to insult but there are to many inspectors that are not trained properly or do any research.

The conductor material can be read on the cable sheath. The panel doesn’t need to be opened to see. Look at the exposed sheath near the panel.