In the late 1960s and early 1970s aluminum wiring was sometimes substituted for copper wiring in residential electrical systems due to the sudden escalating price of copper. Although properly maintained aluminum wiring is acceptable, aluminum will generally become defective faster than copper due to qualities in the metal.
If an inspection reveals a home has aluminum wiring the inspector should suggest it be evaluated by a qualified electrician who is experienced in evaluating and correcting aluminum wiring problems. Not all licensed electricians are properly trained to deal with defective aluminum wiring.
The Consumer Product Safety Commission recommends two methods of correction for aluminum wiring: Rewire the home which can be very expensive and in most cases impractical, or Copalum crimps which cost about $50 per outlet or switch. Although not recommended by the CPSC, pig-tailing or using anti-oxidant paste on connections are other ways of repairing aluminum wiring. Copper and Aluminum wire should never be connected except using special anti-oxidant paste and crimped with approved clamp connectors. If wire-nuts are used they should be approved for use with aluminum wiring.
In most cases inspectors may instruct their clients to talk with their insurance agents about whether the presence of aluminum wiring in their home is a problem that requires changes to their policy language.