Dear Suzy.
We live in one of those houses where the contractors took every shortcut
they could think of and topped it off with aluminum wiring. We’ve been nervous
about the wiring every since we moved in and have asked a number of people
advice. Everyone suggests something different: 1. Rip out all the wire and
replace it with copper. Our neighbors did this and they are living in a drywall
hell a year later. 2. Put in CO/ALR switches and wall outlets — replacing all
the “out of code” and likely to burst into flames original ones. 3. Run new
copper wire to the heavy use areas like the oven, microwave and dryer and
forget about the rest. 4. Use new purple twister things that can go from copper
to aluminum with impunity and safety and patch copper wiring at every switch
and wall outlet and use regular copper plugs. An electrician insisted this was
the only option at $18/outlet.
What do you think? How dangerous is aluminum wiring? Are there warning
signs of aluminum fatigue? How many homes in Austin have aluminum and how many
burn?
Many thanks,
Belle Z
Dear Belle,
Because of the expense of copper during the 1970s, aluminum wiring became
quite popular — along with leisure suits, Donna Summer, and avocado
appliances. What a decade, huh?
Then aluminum wiring, along with leisure suits, were implicated in a number of
house fires. John Doyle, a TEXFIR analyst (information specialist) with the
Austin Fire Department, says that in 1995, 71 fires were electrical-related. Of
those, 29 were due to wiring and of those, six were aluminum. So far in 1996,
aluminum was indicated in only one of the 17 fires cause by faulty wiring. None
by leisure suits.
So, I don’t think you should panic and I don’t think you should resort to
Suggestion 1. (Drywall dust is probably more hazardous than the wiring.) In
fact, Lee Verver, an electrical plan reviewer for the City of Austin, told me
aluminum is still allowed in new construction in town, but only in wiring
running directly from the breaker box to an appliance, like the oven or the
dryer. It is not allowed from outlet to outlet. (This would shoot down
Suggestion 3, don’t you think?)
The main problem with aluminum wiring is a phenomenon known as “cold creep”.
When aluminum wiring warms up, it expands. When it cools down, it contracts
and, unlike copper, loses a bit of tightness each time. Aluminum also oxidizes
on contact with certain types of metal, increasing resistance and heating.
Maybe you’d feel better if you turned off all your breakers and did a little
electrical sleuthing yourself. Inspect your outlets and switches, which should
be rated for aluminum wiring, stamped with “Al/Cu” or “CO/ALR”.
(Remember to turn off all the breakers, unless you want to hear Donna Summer
playing permanently in your head.) One source quotes the cost of professional
replacement of outlets at $3-$10 a piece (which cancels out Suggestion 4,
yes?), but also says it’s a project a diligent homeowner could tackle. After
all, who’s more concerned that the job be done right than the folks sleeping in
the house? Wires should be wrapped at least 3/4 way around the screw
in a clockwise direction and tight, although repeated tightening of the screws
can make the problem worse. “Push-in” terminals are an extreme hazard with
aluminum wiring should be redone with the proper screw connections immediately.
(Turned off those breakers, yet?) Signs of overheating are darkened
connections, melted insulation, or “baked” fixtures.
Any non-rated receptacle can be connected to aluminum wiring by means of a
short copper “pigtail.” Connections between aluminum and copper wire must use a
special wire nut marked for that purpose. The wires must be connected together
using special crimp devices, with an anti-oxidant grease. The tools and
materials for the latter are quite expensive — not practical to do it yourself
unless you can rent the tool.
Now, if only avocado appliances were so easily handled …
This article appears in August 23 • 1996 and August 23 • 1996 (Cover).