I am often asked if aluminum wiring (AL) is going to cause a fire and if people should rewire their entire house to fix the problem. In a word, no. But….
You see, AL wiring in itself isn’t dangerous. As a conductive metal, it’s actually one of the better ones. It’s inexpensive, readily available and lightweight. In fact, airplanes are wired with AL. So are spaceships. Yup, you heard that right. Basically, anything that needs to be exceptionally light often has AL wiring. Often times not exclusively, but always some. “But there always seems to be stories about faulty wiring forcing emergency landings or worse” you say. And that is correct. More often than not though, it’s the insulation or coating on the wire that has failed, not the wire itself. Even gold wiring would fail in those situations.
So, back to aluminum wiring in a residential setting. Believe it or not, with the exception of the house itself, the industry is full of AL wiring. All the powerlines are AL. Utilities have been using AL for power distribution for over 100 years. Even the conductors that attach to your house are AL. The utility uses AL conductors because of the cost savings past the conductor itself. AL is cheaper, great. But because it’s lighter, the utility doesn’t need as many power poles to hold it up. Big cost savings there. It’s also more malleable, which just means it’s easier to work with (given its size relative to copper). This translates into savings again because the linesmen can work faster.
So, if AL is cost effective, lighter and just as efficient at carrying current, not to mention successfully used in other industries around the world, why is it so scary in a house? Why do we no longer use it in modern day construction? The answer to that has a few parts.
Aluminum vs. Copper Wiring
AL was used in residential wiring from the early 60’s into the mid-to-late 70’s. Copper (CU) was at a ridiculous price and AL had a fairly good track record (up to that point). It kept the material costs low so that houses were still affordable, and it was a technology that wasn’t completely unused in the industry (see above) already. Where-in lies the problem, is that AL and CU wiring are completely (almost) incompatible. They hate each other.
A little bit of chemistry and physics here. We’ll start with the physics. AL expands and contracts when heated and cooled way more than CU. So much so, that if the two are attached together in a twist, the expansion and contraction of the AL will ultimately work the connection loose. As it gets loose, it arcs. The arcing creates soot and heat, which builds up causing more arcing, more soot, more heat. Again and again. Then fire. This is also a problem with screw type connectors (on every plug and switch). The screw terminal will ultimately loosen over time until there is a resistive failure and a fire starts.
Now the chemistry, AL oxidizes faster than copper. Think of the legislative buildings in this country. They all have those green roofs (it was just replaced in Regina). That’s the copper oxidizing. That roof was at least 100 years old. If those roofs were AL, well, they aren’t, so you probably know why. To add to the dilemma of AL and CU, when CU is in contact with AL, the oxidizing process is accelerated on the AL and it actually can turn to dust. You read that right. The AL will actually turn into a powder (if it doesn’t start on fire first).
On top of those 2 major issues with AL conductors, is the fact that AL just isn’t as robust as CU. AL is so soft that you can nick it with spoon, bend it a few times and it just breaks off. Not exactly what we want, a bunch of construction workers being around all day (think bull in a china shop).
Where current homeowners have the issue with AL wiring, is that all of our devices (plugs, switches) and tools (marrettes, cutters) are rated for CU only. Not only are those old toggle switches and duplex receptacles out-of-date and yellowed and cracking, they have been getting switched on and off and plugged into and out of for over 50 years! It’s time to replace them, sure, but with your best intentions, as you replace them you are creating a very dangerous space. As you finally decide to develop your basement, you are unknowingly tying your new CU wiring into the old AL wiring. Again, just asking for trouble.
What You Can Do If You Have Aluminum Wiring in Your Home
So, what can you do? Is rewiring your home the only way to guarantee a safe home? Not even kind of. Rewiring your house would be hugely expensive and a major inconvenience. Unfortunately for regular tradespeople, a donated room for a 3 week stay at the Days Inn (thanks Mike Holmes) isn’t in the cards. What you can do is hire an electrician to come into your home and do an inspection. There are steps that can be taken once they have determined that you do, in fact, have AL wiring in your home.
There is a product out there (De-ox) that prevents the oxidation of AL wiring and connections. The electrician will then add a small piece of CU wiring (called a “pigtail”) to each conductor that needs to be used to make the new CU rated plugs and switches work. They will coat that joint in De-ox and use a special rated marrette to ensure that there is no chemical breakdown of the AL and that there is no oxidation.
Call An Electrician
If you live in a house that was built between 1960 and 1980 and you think you have the original plugs and switches or if you have new style decorator (Decora) plugs and switches in a house built in those “questionable” years, it’s probably worth investigating. It won’t take the electrician long to determine if you have AL wiring and if maybe steps have already been taken to alleviate the issue.
The last place to be aware of is that sweet spot in the basement, the “rumpus room” or “man-cave”. These spaces are notoriously done by “do-it-yourself-ers” or local handymen. While I certainly encourage picking up some tools and looking after your investment, playing with AL wiring is only for the pros. It is very common to find basement circuits just pulled off of existing upstairs circuits.
If you live in a home with AL wiring, there isn’t anything to be overtly worried about . But, for a little peace of mind, it is definitely worth the inspection. Plus, it can present you the opportunity to finally update the look and feel of your home with new, modern looking devices.
If you’d like to discuss more or have a wiring situation you would like a professional electrician to look at – give me a call at 306-551-5254!