Aluminum Wire Burned Outlet

Aluminum Wire in Branch Circuits

When I’m performing a home inspection on a house built around 1970, I usually get the question, “Does it have aluminum wire?” Let’s talk about what the issue is, and what your options are if you are looking to buy a house that has aluminum branch wiring in it.

What are branch circuits? 

Branch circuits are circuits that power the “small” stuff like your lights, outlets, and small machines (think dishwasher, disposal, etc.) Aluminum wiring was first used as branch circuits around 1965 during a copper shortage, and was used in homes until the mid 1970’s.  It’s the small 15 and 20 amp breakers in your electrical panel.  The larger wires (usually 240v stuff) and the main power lines coming into the home are typically aluminum but do not have any issues.  

Facts about Aluminum Wiring

The Consumer Product Safety Commission (CPSC) released a “Repairing Aluminum Wiring” pamphlet that you can download here.  Don’t be foolish and try to use it as a how-to guide.  It’s meant to explain what can be done by an electrician who knows what he or she is doing.  Here are some interesting facts for you:

  • There are an estimated 2 million homes wired with aluminum wire.
  • The problem is the connection points and splices at junction boxes, outlets, switches, etc.
  • A national survey conducted by Franklin Research Institute for CPSC showed that homes built before 1972, and wired with aluminum, are 55 times more likely to have one or more wire connections at outlets reach “Fire Hazard Conditions” than homes wired with copper.
  • On April 28, 1974, two people died in a home in Hampton Bays, N.Y. Fire officials determined that the fire was caused by an overheated aluminum wire connection at a wall receptacle.

When I find aluminum wiring, it seems I always get the question, “Do you think it will be a problem?”  Another popular thing I hear is “If it hasn’t been an issue in 40 years, it probably won’t ever be one.”  Wait….what?  People downplay the issue in their minds because of the scope of the potential problem.  It’s not convenient for them to have to deal with this right now.  But it is real, and it can’t be ignored.

Aluminum and Copper Wire

Here you can see what aluminum wire looks like next to copper wire.

What are the issues anyway?

Aluminum wiring has several unique traits that its copper counterpart does not.  All of these add up to the reason it’s no longer used.

  • Aluminum is Soft – When you tighten the set screw down on an outlet or switch, the aluminum wire will actually continue to flatten out a bit over time – even after you stop torquing the screw.  This will cause a loose connection.  Loose connections cause arcing.  Arcing causes fires.
  • Thermal Movement – Everything moves with temperature.  Aluminum wire is no different.  When the wire has electrical current flowing through it, it heats up. When it heats up it expands.  The issue is that aluminum expands more than copper. Over time this swelling and shrinking can cause a loose connections.  Again, arcing and fire.
  • Oxidation – When aluminum wire is exposed to oxygen it oxidizes. This byproduct is called aluminum oxide.  This stuff can deteriorate the connection.
  • Corrosion –  When moisture is added to the mix of aluminum wire, you get galvanic corrosion at the connections.
    Damaged Outlets

    Fire damaged receptacles from aluminum connections.

    Aluminum Wire Burned Outlet

    Here is an outlet that Home Inspector Charles Buell of Seattle Discovered.

I have aluminum wire. Now what?

The first thing you do is get an electrician experienced with aluminum wiring to come check every connection they can possibly get to in the house.  Will they be able to check them all?  Doubtful.  Most houses have junctions behind drywall or in the attic we can’t see or know they are even there.  According to the rulesthere should never be concealed junctions, but the reality is that people don’t always obey the rules.  Having ol’ sparky come check things out can be pricey, but his house call is much cheaper than a house fire.

What can be done to minimize the risk?

There are several products on the market designed to help minimize the risk when dealing with aluminum wiring.

1.  One of the more popular products I find people know  something about are the specially rated outlets and switches made for aluminum and copper wires. These are marked with a CO/ALR on them.   CO=copper – ALR=Aluminum. Would you know to get these for your house if you had aluminum wire?

Here is a scenario for you: 

Being the hip, young couple that you are, you’re ready to tackle some DIYing this Saturday.  So your normal Friday movie date is replaced with a shopping trip to Lowe’s.  You get your paint, brushes, tape, flooring and so on.  Your better half proclaims those ugly almond outlets have got to go in lieu of some nice new white ones.  No worries, right?

You stroll to the electrical aisle and reach for those shiny white outlets.  You need 5 for the living room.  Better get 6, just in case.  How much?  $.68 cents.  No sweat.

You grab your 6 outlets and start to walk away.  Out of the corner of your eye you see another receptacle that looks identical to the one in your hand, except it’s almost $4 bucks.  What?  $4 for one!  I don’t think so.  Let’s roll babe.

2.  There are special connectors called AlumiConn available.  These are approved  by the CPSC, but at nearly $4 each, they are not a cheap option.  Understand that is $4 per wire; per connection.

AlumiConn Connector

AlumiConn Connectors are an option, but they can get expensive.

3.  Another product is the COPALUM connector.  This system uses a special clamp, crimping tool, and heat-shrink to create a copper pigtail off the aluminum wiring.  You must be certified to use this system.  Some areas don’t have anyone available who is certified in using the COPALUM system.

COPALUM Connections

COPALUM Connections splice onto the old aluminum wire

4.  Total Replacement of the aluminum wire itself.  This is, of course, the safest of all options.  It is also the most expensive.  Cost will vary, as every house is different in the process used to replace the wire.  You’ll need to speak with an electrician to get an idea of what you can expect.  Keep in mind this is typically thousands of dollars.  It’s not a cheap process.

If you have aluminum wiring in your home, you need to get that electrician out there ASAP.  If you are not sure if you have aluminum wiring or not, a reputable home inspector in your area should be able to come out and  take a look for you.  You shouldn’t take the cover off of your electrical panel yourself unless you know what you are doing.  There are things in there that will kill you.

You have options in what can do.  You can repair or replace.  Either is better than nothing at all.  And when it comes to situations like this; it’s never a problem until it becomes one.

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Ben Hendricks

owner at ABI Home Services
Hi, I'm Ben, and I inspect houses.I grew up with a hammer in my hand, and have been a professional home inspector for 10 years.My blog is here for info about Home Inspections around the Louisville KY area, and just about anything construction related.
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