Is old Aluminum house wiring safe to work on?

[Willabe]

Has anyone here worked with 50 year old aluminum 10 gauge romex house wiring?

The house we bought when we moved out here to Rochester NY area has mostly aluminum 10 gauge romex house wiring. The house was built in ~'73, I think. I talked with a couple electricians out here and they said they wont even touch any old aluminum house wiring.

They said the aluminum gets brittle as it ages and will often break inside the insulation pulling it out of the junction box and pushing it back in again. Are they being over cautious? Or are they just being to rough with the old wiring?

The old original outlets are very loose when you plug a power cord in. Very little grip, bump the plug and it will fall out of the socket.

We're having our house painted and have moved 90%+ of our things down into the basement. So now would be a good time for me to change all the old original outlets and switches.
     
At the big box stores here, all the duplex outlets, wall switches and circuit breakers say for aluminum or cooper. In the Chicago area all the duplex outlets, wall switches and circuit breakers all say cooper wire only. So I guess there's a lot of houses with aluminum wire out here? 

I have a tube of anti-corrosion paste your supposed to use with aluminum wire. They sell it at all the stores here. Hit the aluminum wire with a little emory cloth or fine sand paper, coat the lead with the paste, then make your connection with a switch/outlet that's rated for aluminum wire.

If I be very careful with those junction box wires and don't get rough with them do you think it will be ok for me to change all my outlets and switches?

It is 50 year old wire. But I wouldn't be too worried about 50 year old copper wire. I'd just be a little gentile with it.

           Thanks guys,   Willabe
 

[sluckey]

Is the wire really 10AWG? You will likely have to buy more expensive 20 amp switches and outlets. That wire probably won't fit modern 15 amp stuff.

[Willabe]

Yes, it says 10 Alu. on the romex cover sleeve. And I can see the striped wire in the circuit breaker box. It's a little bigger than 12guage.

I thought maybe they used the 10 guage to get to a 20 amp circuit rating?   

I was thinking the wire will fit the clamp type outlets/switches? The kind that you stick the wire in straight behind a metal plate that you then tighten/screw down.   

[Willabe]

Went to an electrical supply house this morning and talked with an electrician.   

He said they wont touch a house with aluminum wire. Because if they touch it, by state law, they are now responsible for an electrical house fire.

He said alu. 10 gauge wire is only rated for 15 amps. If you run 20 or more amps through it, the aluminum starts to break down and gets brittle. Everything I'm finding on line says 10 guage alu. is good up to at least 25A, depends on the temp.

I'm thinking if these guys are correct on what causes the alu. to get brittle, I should be good? All the alu. wire circuit breakers in my main panel are only 15A.

I also talked with my neighbor this morning. He works for a company that fixes all the pumps and registers, etc. at gas stations. I asked him if his house has alu. wire, he said this whole subdivision was built with alu. wire. He said he has changed a few outlets in his house and had no problems. He said he was just very gentile with the wire when he changed the outlets.

And I know my neighbor on the other side of our house told me she had all the outlets/switches in her home changed. She has alu. wire too. She has had no problems.

[acheld]

I may be mistaken, but many (?most) modern outlets are rated Co-Al, but that is a great reason to buy from your electrical supply house as they will know.

This might be a situation where "if it ain't broke, don't fix it" applies. 

[PRR]

More fallout from VietNam, when the US was throwing copper in a swamp.

There's also different alloys and ages of "Aluminum". We didn't know what we were doing. After the fires started, they changed both alloys and screws, and then changed them again.

Yes, in small jobs #10 Al replaces #12 Cu, carries 25 Amps but is NEC limited to 20A in ordinary devices because temperature rise. But house wiring in service for 50 years already has real problems.

If it was 10 months ago, you could fast-sell this house to a sucker. But that boom is over.

I would try like hell not to touch it. Any critical loads, I would run new wire and probably a new sub-panel. If you were planning to open walls, that's the time. But if you are just patching and painting, I suppose you plan a decades-long moratorium on trenching, like the town does when they re-pave the street.

[Willabe]

Ok, thank you PRR.

Still looking around the house room by room, still thinking it through. Maybe not as bad as I thought.

I'd say a little over 1/2 the house the Al wire has been replaced with Cu. And the Cu is in the rooms we use the most, family room, finished basement, master bath, and most of the kitchen.

   Willabe

   

[Lectroid]

I have also replaced outlets/switches connected to Al Romex and have had no bad outcomes.  (I know, "--Yet", right?)  If you are gentle and deliberate in your replacements, you should be fine.

Or cough up $2500 or so, rewire with Cu, and sleep better.

 

[DummyLoad]

Ok, thank you PRR.

Still looking around the house room by room, still thinking it through. Maybe not as bad as I thought.

I'd say a little over 1/2 the house the Al wire has been replaced with Cu. And the Cu is in the rooms we use the most, family room, finished basement, master bath, and most of the kitchen.

   Willabe

   

If the dryer, washing machine, stove, HVAC are Al wire then replace with Cu wire as quickly as possible. Get an IR thermometer, turn on load and measure temp rise at the wire to outlet junctions.

--Pete

[PRR]

He needs expert help and it is sad that experts can't help because lawsuits.

But the HIGH current loads will generally have Al-suitable terminations. Tinned with large clamping force.

[66Strat]

The Beverly Hills Supper Club fire in 1977 was blamed on aluminum wiring, and/or the mafia. I believe that it was around this time that aluminum wiring got a bad name. The power supply line coming in to my house is aluminum. I don't know but I believe that high voltage power lines are aluminum.

[PRR]

Pretty much ALL wiring other than on 2-dollar devices (residential switches and outlets) is likely to be Aluminum. It takes more care in connections but is FAR cheaper. I forget just where, but at the 100A (whole house) level even un-rated wire clamps do OK on prepared Al conductors; it is the hundred $2 15A device joints which won't stand the oxidation and thermal expansion.

> Beverly Hills Supper Club fire

"...report on the fire called the club's wiring an "electrician's nightmare", and alleged multiple, wide-ranging code violations. Bridgetown electrician ,... said, "I cannot believe that any of this was ever inspected."

[66Strat]

At the time, I seem to remember the types of receptacles used being incompatible with aluminum wire, causing galvanic reaction that induced corrosion in the connections. I had family that lived in the area at the time.

[66Strat]

There are rebates for electric wiring (up to $2,500) and electric load service center (electric service panels) (up to $4,000) included in the 2022 Inflation Reduction Act. This could help to defray the cost of rewiring your home to replace the aluminum wiring.

https://www.seia.org/modules/electric-home-rebates