Copper wire - what is this stuff

Today’s inspection. 2005 build never lived in home.

Feeder wires look like copper but there some of the strands are discolored.

Ground wire is discolored by what looked like a coating of some kind.

Some of the visible wire conductors at breakers looked almost burnt, but none of the insulation was discolored at all, so I don’t really think it was.

Any ideas what this is?

Why it is there?

Is it a problem?

How would you call it out?

Unknown substance on wires.jpg

Feeder wire.jpg

Hi to all,

Kevin, to me this just looks like oxidization on the copper, probably due to the fact that the home has not been lived in and is possibly damp from lack of heat on the property.



Sulfur gas in the water around here causes that all the time. Around here 12 gauge wire is mostly used because 14 will be eaten through in no time. If this happens around your area you may suggest to client a water test be done.

I believe it is oxidation but in my experience at least it is unusual to see that much around here in a newer home.

I pointied it out and moved on.