Copper Wiring vs. Aluminum Wiring
In the 1960s through the 1970s, copper prices were through the roof so home builders found an alternative: aluminum. While it may seem like a sound alternative at first thought, it was quickly discovered that aluminum wiring was by no means comparable to copper. Aluminum wiring is a fire hazard if not properly installed.
The Issues With Aluminum
Aluminum wiring doesn't just increase the risk of a house fire, it can also lead to hot electrical connections, flickering lights, and burned or melted insulation wiring. These signs of overheating are what led to house fires to begin with.
The main issue is that aluminum is a softer metal than copper. While stripping aluminum, it's much easier to nick it, which creates hot spots in the conductor that leads to overheating. Later on, electricians learned that a new method was required to safely use aluminum wiring.
Aluminum also expands. When an appliance is demanding electricity from the circuit, the conductor will heat up. With aluminum wiring, however, the aluminum will expand at a much greater rate than copper does, leading to the conductor creeping out from the terminal screws and leading to a loose connection. This could spark a potential fire.
Aluminum also corrodes and rusts differently. On steel, rust is red. On copper, it's green. On aluminum, it's where! With copper, rust isn't as big of a problem compared to aluminum since copy rust is electrically conductive. This means it still lets electricity flow and it doesn't interfere as much as the rust on aluminum does. When aluminum forms rust, it is not a good conductor of electricity. This leads to resistance and reduced flow, which can then cause overheating.