Aluminum Wiring vs. Copper Wiring: How to Choose

If you inspect the in-wall wiring in your home or business, aluminum wiring or copper wiring is likely what you’ll find. While wiring isn’t the most attractive element of your home, it’s an important part of it nonetheless. Aluminum wiring regularly appeared in homes from 1965 to 1973. When building a new home now, it’s standard practice for electricians to use copper wiring only. But if you still have aluminum wiring in your older home, it’s worth considering a copper wiring replacement job.

Aluminum Wiring Pros and Cons

Aluminum wiring can be dangerous as it ages. According to the U.S. Consumer Product Safety Commission, an aluminum wiring connection at an outlet is 55 times more likely to create a fire hazard than a copper wiring connection in the same place. 

Because of these dangers, builders rarely use whole-home aluminum wiring these days. The problems with aluminum wires are many, and they’re often unpredictable. Aluminum tends to build excess heat in areas of stress, such as where it connects to an outlet or where it bends. If the heated aluminum breaks or loosens, this can potentially lead to a fire.

The wires are typically hidden behind walls in your home. This means you likely wouldn’t notice the problem with the wiring until you see the warning signs of an electrical fire, which is why it’s so important to be proactive about preventing electrical fires.

Copper Wiring Pros and Cons

Copper wiring is the modern standard for wiring in homes, as it has a far lower chance of leading to an electrical fire. It also carries power much more efficiently than aluminum wiring.

Aluminum Wiring vs. Copper Wiring

If you’re thinking about a rewiring job and considering aluminum wiring versus copper wiring, consider these key factors to help you decide.

Appearance

Almost all electrical wiring has a polyvinyl chloride (PVC) thermoplastic sheath around it that typically is black, red, white, blue, yellow, or green (each wire color indicates a different function). The end of the wire should have a small amount of copper or aluminum sticking out of the sheath. 

Copper has a bright brownish or bright orangish color, similar to a new penny. Aluminum is a shiny silver color. Since all wiring is covered by sheathing with very little exposed metal, you won’t be able to tell the difference between the wire material with a quick glance. Plus, no one besides your electrician will see your wires.

Most attractive: Tie

Durability

Copper wiring lasts much longer than aluminum wiring. One of the reasons is that copper has a far greater tensile strength than aluminum, which means it’s significantly less likely to break when placed under the stress of being bent or curved (which you must do to install a light switch or outlet). Broken aluminum wiring could create electrical shorts and increase the chances of a fire.

Additionally, copper is not susceptible to corrosion. Corrosion can shorten the lifespan of aluminum wiring and weaken it, increasing the fire hazard. 

As electricity travels through wiring, it generates heat. Copper wiring does not expand as much as aluminum when the temperature increases, which further contributes to copper wiring’s durability.

Most durable: Copper wiring

Price

Aluminum wiring costs less per linear foot than copper wiring, which is why you may find it in certain installations. Perhaps the previous owner was trying to save money when installing wiring and chose aluminum instead of copper.

Expect to pay about half as much for aluminum wiring versus copper wiring for the same amount. However, buying aluminum wiring opens you up to many potential risks that could lead to you needing to replace it all in the future anyway. Aluminum wiring may have a lower monetary cost, but the cost of your safety is much higher.  

If you need to replace old aluminum wiring with copper wiring, the cost to rewire a house is typically $10,000 or more.

Lowest price: Aluminum wiring

Ease of Installation

Because aluminum wiring weighs less than copper wiring and has a greater level of malleability, it’s generally easier to work with during installation for novices. 

For people who don't have a lot of wiring experience, aluminum is easier to wrap around the terminal screws on a light switch, for example. Copper is harder to bend into place. However, for an experienced electrician, working with copper wiring is not a problem.

Easiest to install: Tie

Maintenance

Being able to predict when aluminum wiring or copper wiring needs maintenance is extremely difficult because the wiring is inside the walls and not visible. 

Since aluminum wiring is susceptible to breakage and corrosion over time, it could end up creating an electrical short and a fire. It could also become loose at the site of a connection because of these issues. Occasional inspection and maintenance are very important for homes with aluminum wiring.

Copper wiring is far more durable and far less susceptible to breakage, so it won’t need as much maintenance and inspection as aluminum wiring.

Easiest to maintain: Copper wiring

Length of Life

One of the reasons electricians recommend replacing aluminum wiring throughout a home with copper wiring is because of the greater lifespan of copper wiring.

Aluminum wiring could easily suffer breakage or corrosion that shortens its lifespan, while copper wiring rarely faces these problems. HomeAdvisor estimates that copper wiring can last more than 100 years when installed properly.

Greatest length of life: Copper wiring

ROI

Although copper wiring has a greater initial cost than aluminum wiring, its far longer lifespan gives it a greater return on investment. 

If you were to install aluminum wiring in your new home (which rarely occurs these days) to try to save some money upfront, you would be facing the cost of replacing the aluminum with copper at some point in the near future. 

If you install copper initially, you’re probably set for a century or more. Installing copper helps with your home’s resale value, too, as buyers may be wary of purchasing a home with aluminum wiring because of the potential fire hazard.

Greatest ROI: Copper wiring

Bottom Line: Aluminum Wiring vs. Copper Wiring, Which Is Better?

In the aluminum wiring versus copper wiring debate, aluminum certainly has reasons for its usage. You may find aluminum in areas where the wire must carry a lot of power over a short distance in a location that’s easily accessible, such as the line that carries power from the electrical meter to your home’s electrical panel. Copper’s cost could be a bit excessive for this purpose.

However, when you’re considering the wiring inside the walls of your home or business, copper is by far the better choice. Even though it costs more upfront, it has a significantly lower chance of causing an electric fire, so it’s smarter and safer to use copper. 

If you have concerns about any aluminum wiring in your home, reach out to a local electrician for a wiring inspection and recommendations.