While believed to be the cause of many house fires, the everyday use of aluminum wiring in the 1970s is no longer allowed in most cities. If installed correctly, aluminum wire can be as safe as copper wire. When installed incorrectly, aluminum wire can become very problematic.
The expansion and contraction of aluminum wire when it heats up and cools down is where some problems lie. After several warm and cool cycles, the metal tends to lose its ability to remain tight—aluminum, when in contact with other metals, tends to oxidize and cause serious problems. The oxidized aluminum becomes hotter to conduct the same amount of electricity, causing more oxidation. The cycle will eventually cause the wires to become extremely hot and possibly cause a fire.
Suppose you have discovered aluminum wiring or planning to purchase a home with aluminum wiring. In that case, we recommend hiring a licensed electrician or inspector to check for any potential problems.