Aluminum Wiring in Houses: Safety Issues & 3 Repair Options

You’ve probably heard negative stories about aluminum wiring, which might be partially true. But since I can’t read your thoughts, this post will try to dispel the myths, deconstruct the issues and give you full-blown answers on the topic.

Negative information about aluminum branch circuit conductors involves solid aluminum wire for branch circuits. In houses, multi-stranded aluminum wire is still common today for main feeder service wires and circuits like electric stoves.

Solid aluminum wiring has many downsides, including rust and creeping. Solid aluminum wires are particularly unsafe, causing hazard conditions like arcing, which can cause a house fire. While aluminum wiring does have its risks, there are ways to mitigate them and allow the usage of aluminum wiring in your home.

To answer whether aluminum is suitable for electric wiring, let’s see where it all started.

First of all, forget the controversy; aluminum has a rich electrical wiring story. Of course, it is not as highly decorated as copper but worth mentioning nonetheless.

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Is Aluminum Wiring Safe? Common Problems and Safety Issues

Many homeowners and homebuyers wonder if aluminum wiring is safe. Unfortunately, no, unless you’re speaking of multi-stranded wire.

Aluminum has several issues that make it a less attractive wiring option. These issues were discovered when many homes started using aluminum extensively. These are three of the common problems that affect aluminum wiring:

Aluminum Wire is Prone to Aluminum Oxide

Aluminum has several disadvantages when used in electrical applications, as seen in the table below: Higher electrical resistance: Compared to copper, aluminum has greater electrical resistance, so you’ll need bigger wires and more of them to carry the same amount of electricity. Wider spacing between aluminum connections is required because of its higher thermal conductivity.

The metal becomes increasingly damaged as it heats and oxides more, resulting in even greater electrical resistance. Aluminum oxide has a practically indestructible electrical resistance, resulting in even more heat and potential connection difficulties.

On the other hand, copper develops a green patina but still retains its electric conductivity.

Aluminum is Softer than Copper

In the mid-1960s, aluminum branch circuit wiring was introduced to North American houses. Copper was costly, and aluminum was a cost-effective alternative. Contractors used aluminum wiring because it was cheaper, flexible, and lightweight compared to copper. Which also meant aluminum was softer than copper.

Because aluminum branch circuit wiring has a lower conductivity than copper wire, it requires a larger diameter wire. As aluminum heats, it expands and retracts as it cools, causing loose connections in breakers, wiring connections, outlets, switches, and light fixtures.

Aluminum Wire is Prone to Loose Connections

Typically, when electricity travels through the wire, they heat up. In the case of aluminum, its wires tend to overheat because of its disposition.

When there’s continuous contraction and expansion, the wire connections would loosen and cause the wire to creep out under the screws causing circuits to arc. As a result, aluminum wiring would routinely trip breakers, or worse, cause house fires.

However, aluminum was also used for bus bars inside older brands of electric panels. The bus bars would melt and fuse breakers to the bar, resulting in breakers that would fail to trip when an arc or overcurrent happened. The main culprit was Federal Pacific Electric, but other panels like Zinsco and others were not immune to problems.

Is Aluminum Wiring Bad?

For the most part, aluminum wiring has a bad reputation, and it’s with good reason. We’ve already seen why copper has wider usage than its wiring counterpart.

According to the U.S. Consumer Product Safety Commission (CPSC), since 1965, there have been approximately two million aluminum wiring installations in homes and mobile homes. A house with aluminum wiring is 55 times more likely to catch fire than others, let’s say with copper wiring.

Even so, the idea of electricity at home is a fire hazard regardless of the material used. As we described earlier, most homes with aluminum wiring were built between 1965 and 1972.

Aluminum wiring significant risks stems from the connections. If you install the wrong receptacles and conductors, you increase the risk of electrical fires.

When connected to the light switches and wall outlets or other wires in junction boxes, aluminum wiring presents a problem. Considering the number of connections your home might have, you get an idea of the underlying risks.

The signs we highlighted earlier make the issues easily identifiable, including warm cover plates, overheating, and flickering lights. Overheating is the primary cause of fires by aluminum wiring. It can overheat more than copper, which means the coating deteriorates over time, exposing the wires.

Other factors individually or collectively also cause overheating in solid aluminum wires. Again, its lightweight character contributes to its quicker wear and tear. The houses with aluminum wiring are 50 or more years old; thus, the wear could be extensive.

If you come across a home with aluminum wiring, all you need is to put the proper precautions and measures to reduce the risks. Because opening walls to replace the aluminum wiring is costlier than the alternative.

Is It Okay To Buy a House With Aluminum Wiring?

So far, we’ve identified the issues affecting aluminum wiring, and these issues present a risk when buying or selling a house with aluminum wiring. It is okay to buy a home with aluminum wiring provided that the following are considered first:

  • Consult a licensed electrician to help you examine the type of wiring installed in your potential home. They can observe the extent of the tear and whether you need to replace some of the installations. Mostly, they look for any critical issues with the wiring and their aluminum wiring connections.
  • The electrician report should determine your next move. If they recommend a replacement, go ahead and come up with costing for the entire rewiring. In this case, the new copper wires will be run across each branch circuit. Remember, buyers may use this during home negotiations.
  • As a precaution, wires should not be overloaded. The electric loads should be distributed among the many cables in use. Under normal circumstances, aluminum overheats from continuous expansion and contraction. Now can you imagine what would happen if one wire is overloaded? You get the picture; that’s a potential fire hazard right there.
  • You need to know the insurance costs for a house with aluminum wiring. Insurance companies have a problem with ensuring homes with aluminum wiring. In that case, you could do some shopping around to see whether any insurance company will be willing to insure your home.

Should You Replace Existing Aluminum Wiring?

Aluminum wiring is plagued with several issues that are hard to ignore. Most homeowners console themselves that their wiring has been around for more than 50 years. In normal circumstances, that is a commendable achievement.

Because it means that your wiring served you well for a long time, due to the potential risks, the replacement could be the best solution. You replace the aluminum wiring with copper wiring. Even so, there are considerations you need to make before settling on a replacement. Here are some of them:

  • Aluminum wiring replacement does not come cheap. You must pay for the labor to take out the old wiring and replace it with the new stuff, not to mention the cost of materials and tools.
  • The replacement process can be tedious. Since the process is quite rigorous, it might force you to remodel your house. While this is not a disadvantage per se, some homes are best left as they are. Remember, these homes still have fixtures or designs from 50 years ago you would want to retain. It could be that’s what attracted you to the house in the first place. However, if the aluminum wiring calls for remodeling, you may go ahead and remodel it.
  • Forfeiture of insurance. Most people will never use it because of bad publicity, and few insurance companies are willing to insure a home with aluminum wiring. Replacing your aluminum wirings may also remove the insurance that comes with it.

One of the reasons aluminum got so much bad publicity was its problems. Realistically, there’s no way aluminum would have competed with copper in electrical wiring. When manufacturers and authorities discovered the issues affecting aluminum, they went to look for a solution.

Some of the solutions they found improved the performance of aluminum considerably. They even created a better-performing aluminum alloy. The only problem was that they discovered the answers when too late.

By then, most people had dropped aluminum as a choice in wiring. Manufacturers had a hard time marketing aluminum to the masses. This explains the myths associated with aluminum wiring.

Due to the cost implications, homeowners decided to retain their wiring while adopting these newfound solutions. However, sellers should remember that the sheer presence of aluminum wiring can scare off would-be home buyers.

Additional Repair Options for Aluminum Wiring

The bottom line is that remodeling is the best solution, then go for it. But, if you wish to check out other options aside from replacing aluminum wiring, I compiled some of them for you:

1. The Best Option is to Rewire the House

The best option for repairing aluminum wiring is also the most costly. Rewiring the house with copper wires will be expensive, with the actual cost depending on how many circuits will need replacement. Other updates to the electrical panel will also be a requirement if you choose to rewire the house.

While you get to dig deeper into your pockets, this is an ideal solution for your home. It can cost you between $15,000 to $35,000 or more on average. An experienced electrician will help you develop a specific number for your potential home.

2. You Can Replace All Outlets with Dual Rated Outlets

One way to make solid aluminum branch wiring safer is to replace all outlets and switches you currently have with outlets that are dual rated for both copper and aluminum wiring (CO/ALR). However, you’ll still need to install pigtail copper to aluminum using twister Al/Cu wire connectors or another aluminum/copper rated connector for other circuits and inside junction boxes.

3. Pig Tailing Copper Wire to Aluminum Wiring Safe

There is a cheaper alternative for consideration. Using special connectors, you can pigtail a piece of copper wire to the end of each aluminum wire. It’s a standard repair method in such situations. From the previous observation, aluminum wiring weakness is worse at outlets and switches.

Pig tailing connects a copper wire to an aluminum wire. But you should know most local authorities do not allow copper pigtails. You should confirm this with qualified electricians before undertaking any repairs.

You can’t make pigtail copper and aluminum wire connections with standard wire nuts. You must use approved wire nuts or connectors that are Al/Cu rated. Connections safe include:

Twister Al/Cu Wire Connectors are special wire nuts rated explicitly for connecting copper and aluminum wiring. They are identified by the Al/Cu rating and are purple.

Copper Aluminium Connectors (COPALUM) are special connectors used for pigtail repairs. They are approved by the U.S. Consumer Product Safety Commission (CPSC).

In a real sense, this electrical repair is considered a long-lasting solution and requires a qualified electrician to use special connectors to attach the pigtail. Special crimping tools rely on pressure to improve the aluminum connector to the copper conductor.

Afterward, a heat-shrink insulator is applied after a connection is achieved. Ensure that it’s the only authorized person that performs this action.

AlumiConn Connectors – This method has been around for 15 years now. The U.S. Consumer Product Safety Commission (CPSC) recommends this method as an alternative to the COPALUM.

Unlike the COPALUM, the AlumiConn uses a collection of screws to link with the pigtail repair. You need to ensure that you tighten the screws as indicated in the manual for the best results. If done correctly, the tight screws will offer a safe and long-term solution you may rely on. 

These electrical connections will need to be made at every junction box, breaker, outlet, light switch, and all lighting fixtures. Considering the number of electrical contacts and that even one faulty connection could be missed, rewiring with copper wire is the safest and most permanent repair.

Issues with Homeowners Insurance and Aluminum Wiring

The challenge with aluminum wiring is that most insurance companies shy away from covering such dwellings. In such a case, you will do a lot of shopping before finding an insurance company willing to insure your home with aluminum wiring installed.

To simplify the insurance acquisition process, start by performing any repair methods highlighted above. Afterward, you can get the proper documentation to indicate that you had the repairs done accordingly.

On the flip side, if you are selling a home, it is better to do the necessary repairs before putting the house on sale. In such a way, the potential buyer is aware that the repairs are done correctly. Potential homebuyers can get spooked if they feel that homeowner’s contractors took aluminum wire repairs shortcuts.

In addition to that, the certification you get will make acquiring homeowners insurance simpler. In essence, when the repairs are done in advance, they quicken closing the deal.

It’s not a surprise to see a potential buyer ending the contract after the inspection is done, especially if they are not aware of the solutions available. Plus, they could be avoiding the aluminum wiring repair problem altogether.

You’ll need to talk to your insurance agent before buying a home with aluminum wiring to discover if it’s insurable. The bottom line is that doing the repairs is good for business.

When Did Aluminum Wiring Start Being Used in Construction?

Electricity was invented in the 19th century and mass adoption followed shortly afterward. The inventors were aware that copper was an excellent conductor of heat from the start. So copper was adopted earlier on, even when wiring at homes became a thing.

Some other metals or elements are also good conductors of heat; aluminum is one of them. But aluminum pales in comparison with copper. A few changes allow aluminum to perform almost as well as copper.

Aluminum wiring started gaining popularity in North America after copper shortages in the 1960s. Aluminum became a cost-effective option. However, aluminum was affected by several issues which had to be corrected.

The mass adoption of aluminum meant that builders would change because of consumer complaints. Among the manufacturers’ changes was to use a larger wire than the one used in copper wiring.

In a real sense, aluminum packs a 12 gauge wire while copper packs a 14 gauge one. And for your information, a 12 gauge wire is larger than a 14 gauge wire.

Aluminum got several problems after widespread adoption. Overheating was one of the significant issues that riddled aluminum wiring. Other issues include warm cover plates on receptacles and switches and flickering lights.

Final Thoughts

If you plan to buy a home with aluminum wiring, you may solve the problem through the methods we’ve discussed. Aluminum’s primary concern is not the wires themselves but the connections at outlets and switches.

That’s why some of the less expensive repair methods call for adding copper wires at the connection. Once you put up these solutions, your home is safer. Aluminum wiring overheating is a cause of fires.

The other question people ask is whether it is okay to buy a home with aluminum wiring. There’s nothing wrong with buying a home with aluminum wiring as long as you factor in the cost of repairs (if need be) or replacement.

It is best for the home seller to conduct the potential repairs before putting up the home for sale. One of the disadvantages of aluminum wiring is the lack of insurance. Most insurance companies refuse to insure aluminum wiring in homes. You’ll have to shop around before you can get one that is willing.

Copper usage is widespread because it is superior to aluminum in more ways than one. But that doesn’t mean you won’t find many homes with aluminum wiring.

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Hubert Miles

I've been conducting home inspections for 17 years. I'm a licensed Home Inspector, Certified Master Inspector (CMI), and FHA 203k Consultant. I started HomeInspectionInsider.com to help people better understand the home inspection process and answer questions about homeownership and home maintenance.
DISCLAIMER: The content published on HomeInspectionInsider.com is not professional advice. You should consult with a licensed professional and check local permit requirements before starting any project.
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