Aluminum Wiring


I am not a home inspector but a concerned client from a recent home inspection I had performed last week.

While examining the breaker box my inspector found what he claimed to be aluminum wiring coming out of several circuits. His verbal words to me were “this is aluminum wiring”.

His report was very ambiguous with a large amount of second opinions especially the aluminum wring concern.

My question to all home inspectors reading this post- Through your training and certification, are you required to positively identify aluminum wiring without a second opinion from a licensed electrician?

Thank you for your time.

The NACHI standards of practice indicate so.

Also note that there is also an older copper wire with a tin coating that may appear to be aluminum if you don’t look closely or don’t know what to look for. However I find far more actual aluminum wire than the tin cladded copper.

You are the seller?

I am the buyer. My inspector told me verbally that you have aluminum wiring. In his report, it stated “what appears to be aluminum wiring”.

That is why I asked, as a certified home inspector through NACHI are you required to positivly identify alumimum wire?


If readily visible, yes.

It’s actually fairly easy to identify it’s presence if the service equipment is fully accessible.

In any event, once identified, it’s up to the client to follow up with appropriate evaluation and/or repairs.

It sounds like you feel there is a discrepencay between the verbal “it is” and the written “it appears to be”. Like I said there is a much less common wiring that on the surface may appear to be aluminium. It is an older wire than the aluminum.

If you phone your inspector I’m sure he will clarify his statements for you.

Technically, one could not actually identify aluminum wiring as aluminum without removing it and running it through some identifying laboratory tests. However, based on experience, as well as other circumstances, like the build date of the structure, most home inspectors can “identify” aluminum wiring. But here in my state, I’m not going to “positively identify” aluminum wiring, preferring to let the licensed electrician do that since he is licensed and California has no licensing for home inspectors, even though our jobs require that we know electricity.

So, to answer your question,


Thanks for all your responses. You have been more than helpful. I had a licensed electrician come to the house and positively identify the wires. Turns out they are all copper.


Ya…Tin coated copper.

This is aluminum wiring…(with melted insulation)

I don’t need a laboratory to tell me that my soda can is made of aluminum. AL conductors are easy to identify (positively) if they are visible.

In this case, it sounds like the conductors were tinned copper (as David said).

A couple clues. When was the house built? Al was used in the late 60s and early 70s. Aluminum will be a PVC jacketed cable, not the silvery paper/cloth type jacket. The only color I have seen is white but it might be other colors. It will be one size larger than you would expect for the breaker size. (12ga on a 15, 10ga on a 20). The insulation will be TW, a thick solid plastic, not cloth reinforced rubber or the smaller 2 layer THHN you see in NM-b.
The slam dunk is if you can see the cable jacket and see “AL” or “aluminum” next to the conductor size … but you know that.

Up here in Canada there does exist some aluminum wire I’ve seen personally with the paper/cloth style jacket. I’ve only ever seen it covered green, although the conductors inside are definately plastic insulated. I think its circa 1965-ish. I can’t imagine why this stuff wouldn’t also exist in the US. It does, however, very clearly say AL on the jacket.

Aside from that most is that ALCAN stuff which is plastic all the way. Not sure about the states, but here the “good” aluminum stuff from 72-76 has “ACM” stamped on the jacket along with “AL.”

ODDLY ENOUGH… I’ve seen ALCAN COPPER wire in a 1978 townhouse. Weird eh? Funny since Alcan is an aluminum company.

Anyways I’m just rambling now…

Here are some pics of tinned copper wire, which may “appear to be” aluminum wiring unless you can see all the cut ends (sometimes very difficult to see) or there are other indications to the contrary like markings. Even if you can see the cut ends of some wires, it’s possible to have a mix of different wire types where some are tinned copper and some are aluminum unless all the cables look the same.

Sounds like your inspector called it right that he suspected aluminum wiring (can be a real safety/fire hazard), and to have an electrician disconnect some wires for each type of cable and look at the ends to positively identify them (which is beyond a home inspection, as home inspectors should ABSOLUTELY NOT disturb suspected aluminum wiring).

Older aluminum wiring can be a very serious life safety hazard where you are much better off being safe rather than being sorry …

JMO & 2-nickels … :wink:





Thanks again for all your comments!


Sorry to hear about your misfortune.

Sounds like you probably had “Recommend further evaluation by licensed contractor” in your report several times…](*,)

If that had been true, seems like the licensed contractors should have their licenses revoked. :roll:

Or the inspectors…:roll:

The inspectors here, since they are not licensed at anything, would be well within their area of expertise, of which they have none, by recommending further evaluation by licensed professionals practicing within their area of expertise. But for gosh sake, don’t recommend further evaluation of aluminum wiring by the plumber–no telling what he might do after he pulls his pants up. :slight_smile:

RRAY…Plumber Hater…lol

Not me.
Ms Margarita.

I have heard complaints about the number of recomedations for professional evaluation the typical HI report contains. They ask that if they need a roofer, electrician, plumber and HVAC tech, why did they need an HI?