I agree that connections are the problem. As RBM said, the problem is
esentially only with #12 and #10 wire on 15 and 20A branch circuits.
Aluminum is in common use in larger sizes.
About 1971 UL removed the listing for wire and devices (receptacles,
switches,...) then came out with new standards. The new devices were
marked "CO/ALR". According to gfretwell the new wire was harder and not
as likely to extrude/creep. (Most of the wire in use is "old technology".)
The CPSC appears to have been moving toward a recall (which would have
been enormously expensive), but in the inevitable court case wiring was
ruled to not be a "consumer product" and thus not under the purview of
If anyone is dealing with these aluminum branch circuits,
recommendations on making connections, based on extensive research done
for the CPSC, is available at:
A basic element is cleaning the wire to remove the oxide and applying
I bought the house I'm currently living in in 1987. It was built in
1970 and has aluminum wiring. At the time of sale I required the seller
to swap out every wall receptacle and switch with COALAR units and the
work to be done by a licensed electrician.
Every house in my subdivision was built at the same time with the same
wiring. Neither me nor any of my neighbors (to my knowledge) has had
any problems related to the aluminum wiring. We all have circuit
I used to take off the face plates every year and check to see if the
wire loops were loosening under the screw heads but gave up that
exercise after about 3 years when none were noted to have become loose.
I'm well aware of the supposed risks associated with aluminum wiring and
I would have preferred to have copper. However, my experience has not
been bad. I suspect that if the homeowner respects the amperage ratings
of each breaker circuit and avoids overloads, they will not have
problems. Copper is more forgiving of overloads due to lower resistance
and therefore less heating and attendant expansion/contraction at
Thanks Peter. What is COALAR switches? As best as I could see on
the net it's copper aluminum automation ready switches and I have no
idea what that means? One thing I've learned is that this house
"supposedly" per the owner has copper wiring but personally I don't
trust it to be so unless I can verify it. He did say that in the
early 90's it has a small fire on the roof at the garage end of house
due to a lightening strike. I don't know if that has any connection
to the wiring and since I don't know this owner, I'm suspicious to say
Those are devices with connectors made to accept aluminum.
As practically everyone has responded, the house in question is simply
to old for you to be concerned about small gauge aluminum building wire.
I'm not an electrician. Rather than cut and paste numerous texts or
post a list of web links, I'll simply mention that my previous post used
a non-standard abbreviation for the hardware. It is better known as
CO/ALR. I hate to mention specific brands or search engines, but using
the well known search engine that begins with G, the first page of hits
disclosed several hits (a) describing the hardware and the application
for it, (b) links to well known electrical supply manufacturers current
selling the hardware, and (c) big box and web retailers selling the
hardware. I'm sure you can find all you need to satisfy yourself.
P.S. The "proper" way to deal with a home with AL wiring is highly
controversial depending upon what you read and who is speaking for their
own self-interest. It ranges from minimalist mitigation (CO/ALR)
hardware to a complete rip-out and replacement with CU wiring.
Professional high pressure crimping to CU pigtails for every connection
and junction is a popular but quite expensive intermediate way to deal
with the issue. My biggest problem recently was finding a licensed
electrician who was knowledgeable and felt competent and willing to work
on my wiring. The first few a I called said they wouldn't work on it
for fear of future litigation from me in the event of an electrical
fire, or because they had no experience working on it and couldn't take
the time to get trained.
Doug, there was a report published in 2008 by Underwriters Laboratories and
the National Fire Protection Association titled, "Residential Electrical
System Aging Reserch Project". The researchers tore apart 30 homes aged
30-110 years and evaluated the wiring as they found it It's the best
information available on what to look for with respect to wiring in older
homes including some great pictures showing what you might find. The report
is free to download. Just Google the title.
I was reading this thread till I got to this reply from you.
First off, lightning is NOT caused by the wiring, nor is the wiring very
likely to attract lightning. Lightning mostly hits where ever it is,
but tall metal structures can attract it, such as antenna towers and
even tall trees. Whatever gave you the idea that the fire which they
said was caused by lightning has anything to do with the wiring is just
I think you're being much too suspicious...... I understand you
checking out all the parts of the house for problems, but how many more
people on here will it take to tell you that aluminum wiring was not
used in the 50's. I'd be more concerned about the wiring on the end of
the house struck by lightning having a few charred connections from the
strike. I'd also want to see the attic on that end of the house for
charred wood and structural damage.
If you are that worried, hire a contractor/inspector to check the house.
In most or all places you have that right, as long as YOU pay them. And
why are you asking for prices on the internet? No one knows what prices
are like in your part of the world. That's about as stupid as calling
your doctor and asking him to disgnose your kidney stones over the
A minor problem is that electricians do not necessarily know what the
actual problems and fixes are.
If you are interested you can read:
(also posted elsewhere). You will probably know more than electricians.
The advice is based on extensive research on aluminum connections.
Trivia note, the "R" in CO/ALR is "revised".
Resistance is not a factor. Aluminum wires have a similar resistance to
copper since they are larger - #12 aluminum on a 15A circuit, #10 on a 20A.
Bud, are you familiar with copper clad aluminum? I first saw it when I
worked for an electrical supplier in the early 1970's during a copper
shortage. The company was selling a lot of aluminum Romex and then we
started getting in copper clad aluminum Romex. One day the darnedest
thing showed up from another supplier, copper clad thermostat wire in
18 AWG. I discovered it when I picked up the reel and it darn near flew
out of my hands because it was so light. If you've ever picked up a
hollow display auto battery, you know what I mean. I hadn't seen copper
clad aluminum for years until recently when I got an Email from a
network component supplier for 24 AWG copper clad Cat5 network cable.
I just called my buddy at Inline Electric and he's never heard of copper
clad aluminum Romex so I assume it hasn't made a comeback in the
local electrical supply chain. But dang, copper is getting expensive! o_O
I have never seen copper clad. I haven't seen much aluminum 15/20A
branch circuit wire either. My understanding was that copper clad was
late in the period when aluminum was used for branch circuits to
eliminate the surface oxide problem, which would match with what you
wrote. Given the problems around 1970 I would think copper would have to
get pretty expensive to see aluminum used for branch circuits again.
Would be interesting how trouble free "new technology" copper clad
aluminum wire is, used with CO/ALR devices. Might be as good as copper.
I wouldn't want to use aluminum or copper clad for thermostat or signal
wires either. Opinions of punch down block and RJ jack manufacturers
would be interesting.
I don't believe I've ever seen copper clad either. From the description
I read, it's supposed to be soft and pliable, and when you cut it, you
should see the aluminum center. On rare occasions, I've run into very
soft copper conductors, which I just assumed was a manufacturing issue.
I've also run into very hard, almost brittle copper conductors. Maybe
the soft ones were clad, and my dull pliers just wiped the copper over
Was the cost of copper so much more than aluminum that it made copper
clading cost effective?
When one considers the costs of the R&D to get the ratios right, the
retooling of the factory to manufacture the clad wire (including the
additional spare parts, training of workers and repair technicians,
documentation, etc.) the approval process to get it NEC approved, etc.
etc. it seems that the cost of copper would have to exceed the cost of
aluminum by a substantial amount for a long, long time in order to
make up the cost to switch over to clad.
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