We just inherited a 45-year
old house, and shortly after we moved in we noticed that the lights would
occasionally flicker on and off. Some
switches were hot to the touch. I
contacted an electrician to come over and inspect the wiring. He said that the problem was with the
aluminum wiring used in my house. He
showed me burn marks at some switches and outlets. He said that I should have the whole house
rewired and that can cost thousands of dollars.
My parents were the original owners, and I don’t remember them ever
having a problem. How much of a concern
is it to have aluminum wiring in the house?
D.S., San Mateo
Aluminum wiring has been
used for many years in residential construction and is still being used
today. Properly installed, it is as safe
as copper wiring. In fact, you will
probably find it (to some extent) in more than 90% of the homes, condominiums
and apartments being built today.
The fears and concerns about
using aluminum wiring usually dates back to the late 1960's, because aluminum
wiring got a lot of bad press. There
were several cases where electrical fires had been occurring in houses built with
aluminum wiring. In some homes, people
would have switches and outlets getting hot when in use, and sometimes causing
shocks to individuals, or starting fires.
Before the 1960's, most
homes in California
were wired with copper wire. It was
cheap and easy to work with. Then in the early 1960's the price of copper had
gone way up, and contractors building large housing tracts turned to using
aluminum wiring as an alternative.
PG&E had been using aluminum wiring for years and never had any
What the contractors did not
understand at the time, is that the characteristics of aluminum wiring are very
different from that of copper, and that there were specific installation
standards that had to be followed when using it. Investigations that followed
all of these fires were able to prove that it was not the wiring that was the
source of the fires, but rather the workmanship of how the wiring was
Aluminum wiring is soft, has
a low melting temperature, expands when heated and oxidizes easily. Because of this, aluminum requires that any
connection to it be made in such a way that the wiring will not be able to
loosen. This is usually done with a
special crimping tool and special connectors.
Copper wire on the other hand, is a little more stable and flexible than
aluminum wiring, and does not require the special connectors
The secrete to living with,
and using aluminum wiring, is making sure that it is properly installed with
the proper connections. The National
Electrical Code requires that any fitting connected to aluminum wiring be
approved for use with that type of wiring.
This basically means that you cannot connect an outlet, switch, fixture
or fitting to aluminum wiring unless it is rated to be connected with aluminum
wiring. These devices should be clearly marked with the designation
“CU/AL” or “CU/ALR”. This means that the
fitting is approved for use for copper (CU) and aluminum (AL).
The “ALR” designation means aluminum residential.
What happened back in the
1960's is that the installing contractors were connecting the aluminum wiring
to outlets, fixtures and switches that were designed to be connected to only
copper wiring. The fact that your house
has aluminum wiring should not pose a safety problem if it is properly
Your question seems to
indicate that the problem with the wiring is at the joints or connections to
the switches and outlets. This is where
most of the problems occur with aluminum wiring. Because aluminum wiring expands and contracts
a bit when an electrical load is running through it, it tends to heat up and
loosen connections if it is not properly tightened. This usually results in a switch or an outlet
being warm or hot when touched. Over the
years, this overheating tends to damage outlets and switches. Merely replacing these
devices will fix the problem in most cases.
To ensure the safety of your
electrical system, you should have it inspected by a qualified
electrician. Start by having the
electrician inspect all your outlets and switches. It is possible that there is a loose
connection at some other area, such as a light fixture, junction box, or sub panel. In any case, a good electrician should be
able to trace down all of the problems.
Schneider is a licensed general building contractor and a certified residential
code specialist. He is president of All About Homes, a residential inspection
company, and has been performing code and construction consultations since
1985. Readers may address their comments
to John Schneider, 24326 Mission
Blvd. Suite 7, Hayward,
Ca 94544. Fax number: 510 537-8666. Please include your phone number. Schneider will answer questions of general
interest in the paper. He reserves the right to edit the letter for brevity and
clarity. Readers are encouraged to contact a competent contractor or code
consultant for specific information regarding questions they may have about
2001, John R. Schneider, all rights reserved