Aluminum Vs. Copper Wiring: What You Need to Know

Between 1965 and 1973, aluminum became a common substitute for copper in household wiring. Aluminum was an attractive wiring material because it was far cheaper than copper, which had escalated sharply in price. Unfortunately, after a decade of use, electricians and other industry professionals began to see inherent weakness in the aluminum wires.

Today, the Consumer Product Safety Commission (CPSC) reports that aluminum wiring in homes manufactured before 1972 may be up to 55 times more likely than copper to have one or more faulty connections. These connections can be a fire hazard, leading to loss of property and even loss of life.

Is aluminum wiring dangerous?

Connections made with aluminum wiring become defective much faster than copper. As these poor connections age, they can become increasingly dangerous. Here's why:

• Corrosion. While aluminum doesn't rust, it can develop galvanic corrosion when it comes in contact with other metals in a moist environment.
• Natural vibrations. Electrical current causes wires to vibrate as it flows. The vibrations in aluminum wiring is more extreme than the vibrations in copper wiring, and can cause the connections to become loose with time.
• High electrical resistance. Aluminum conductors must be larger in diameter than copper because it has a high resistance to electrical current.
• Ductility and malleability. Aluminum is easily bent and relatively brittle, and can break comparatively easily when bent. It also develops more resistance as it is bent, which can cause a buildup of heat in the wire.
• Oxidation. Exposure to oxygen causes the outer surface of the wire to deteriorate. The resulting aluminum oxide is less conductive and can become a fire hazard over time.
• Thermal expansion and contraction. Aluminum expands and contracts with temperature changes. These expansions and contractions are more extreme with aluminum than with copper wiring.

Despite these problems, aluminum wiring can last for a long time without any problems. Homes with aluminum wiring still exist today, and have had aluminum wiring for decades. Aluminum wiring that is properly installed and has not been changed since its installation may be fine, but homeowners should be aware of the risks.

Can you get homeowners insurance if you have aluminum wiring?

Some insurance companies will charge higher rates for insuring a home with aluminum wiring. In addition, they may require an inspection of the wiring in the house, and potential repairs as a pre-requisite for insuring the property. If your home has aluminum wiring, you may need to shop around for the most affordable policy. You may also need to get an evaluation from an electrician in order to become insured.

How can you tell if you have aluminum wiring?

Aluminum wires are silver colored, like steel. The aluminum sheathing is also labeled with the letters "AL," or may be labeled with the brand name and the word "aluminum." In addition, your home is more likely to have aluminum wiring if it was built or if an addition to it was built between the years 1965 and 1973.

Why is copper wiring better?

Copper wiring has a lower thermal expansion than aluminum wiring, which means that it doesn't expand as much when exposed to heat. Copper wiring is also stronger than aluminum and less likely to break.

Whereas aluminum can be brittle and will develop more resistance when bent, copper is very forgiving and stable. It's less likely to develop poor connections than aluminum, and is a more durable product. Copper wiring is less dependent upon perfect installation techniques to remain stable, and is less likely to develop problems when wiring repair or changes are made.

I've found a home I'd like to buy, but it has aluminum wiring. What are my options?

Before buying a home with aluminum wiring, it's a good idea to have the wiring inspected by a qualified electrician. You may also want to negotiate a re-wiring of the house with the purchase contract. Work with your real estate professional on this to decide to best course of action.

What is "pig tailing"?

Pigtailing is the process of attaching a short piece of copper wire to the aluminum wire. The two wires are attached to each other with a twist-on connector. The copper wire is then attached to the wall outlet or switch.

Pigtailing can be a way to work around aluminum wiring, if the work is done properly and the correct tools are used. However, pigtailing increases the number of connections and all those connections have the potential to fail. Keeping connections safe is a part of reducing the potential for fire hazard. Your electrician can tell you if pigtailing is a potential workaround for you.

My home has aluminum wiring. What are my options?

If your home has aluminum wiring, have it evaluated by an electrician who can determine whether your wiring was properly installed and is currently stable. Hire an electrician that has experience working with and evaluating aluminum wiring, as not all electricians are very experienced with this material.

Complete Re-Wiring

If your electrician determines that your wiring is in need of remediation, re-wiring is the most effective method of reducing the potential for fire hazard. Some homes are easy to rewire because they have unfinished spaces in the house to serve as access points. In this case, a new copper wire system is installed and the old wiring is abandoned in the walls.

COPALUM Connector

If re-wiring is not practical, your electrician may also recommend using COPALUM connectors to repair your aluminum wiring. The crimp connector attaches a piece of copper wire to the aluminum wire by crimping the two wires together and protecting the connections with a special sleeve.

To be most effective, COPALUM connectors must be installed in every receptacle, switch, dimmer, etc. COPALUM is required to be installed by specially trained electricians. When installed by a specially trained electrician, COPALUM connectors are an effective and safe method for eliminating hazards associated with aluminum wiring. A full list of specially trained electricians who can install COPALUM connectors is available online.

AlumiConn Connector

If a specially trained COPALUM electrician is unavailable in your area, one more way to fix aluminum wiring is to pigtail your aluminum wiring with AlumiConn connectors. These connectors must be installed by an electrician because they can easily be installed incorrectly, thus creating a fire hazard.

Are there are other products that will work for remediating your aluminum wiring?

There are other brands and companies that have come up with ways of remediating aluminum wiring at home. Generally speaking, these solutions are considered temporary by the CPSC and should not be treated like permanent solutions.

How Can You Tell If Your Aluminum Wiring Needs to Be Replaced?

While you may be able to see signs of a poor connection, aluminum wiring can sometimes go bad very fast. The best way to be totally safe is to remediate your aluminum wiring before it reaches the point of being a hazard to your home and members of your family.

That said, here are some warning signs to watch for:

• Lights dimming and brightening, especially when an appliance is turned on
• Light bulbs burn out quickly
• You're seeing smoke or sparks coming from electrical outlets
• You smell melting plastic around outlets
• Small appliances and electrical devices suddenly stop working, even though a breaker hasn't been tripped

Have Aluminum Wiring? Get An Inspection As Soon As Possible

Get help from an electrician as soon as possible to decide whether your aluminum wiring is in need of repair or replacement. Call Add All Electric today to find out more about replacing your aluminum wiring, or to find out more about upgrading your electrical panel or breaker box.