Dealing with aluminum wiring


Bryan FreemanBy Bryan Freeman

Aluminum wiring was used extensively in the residential market from 1965 to 1976, but is no longer a popular wiring material for branch circuits. Problems have been reported from the overheating and failure of aluminum wiring terminations. Symptoms of this include receptacle discolouration, flickering lights, the smell of hot plastic insulation and sometimes an electrical-induced static noise on the radio and/or television.

Aluminum wiring in a home will operate as safely as any other type of wiring if the proper materials are used and it is installed to the manufacturer’s instructions and the Electric Safety Code of the jurisdiction where you live.

If you are trying to sell a home with aluminum wiring, one of the biggest obstacles will be when the potential buyers try to obtain insurance. The insurance underwriter often insists on having the electrical system inspected by a licensed electrician who has experience in inspecting and repairing aluminum wiring.

Your home inspector should strongly recommend that you hire a qualified electrical contractor experienced in repairing aluminum wiring to do a thorough inspection of the electrical system, even if the insurance company does not request one.

The inspection should include the following:

1. Visually check terminations at devices without removing or disturbing the devices.

2. Cut back any damaged aluminum conductors and join these to a copper tail using an approved connector for use with aluminum. These connectors are brown or purple depending on the manufacturer.

3. The copper tail is then terminated at the terminal screws of an approved ordinary device.

4. Sometimes the damaged section can be cut back, removing the damaged aluminum conductors and re-terminated at a new device bearing the marking CO/ALR.

5. Only devices bearing this CO/ALR marking are currently approved for use with aluminum wiring.

6.  Panel board terminations should be checked for signs of overheating.

7. Fuses installed for heavy loads should be temperature sensitive Type D or Type P.

8. Circuits should never be overloaded or over fused regardless of wiring type.

Someone who has not examined the wiring in your house cannot reliably assure you about the condition that this wiring is in. Yet, in response to inquiry by owners or buyers of homes containing aluminum electrical branch wiring, there have been reports that some individuals in the field say the aluminum wiring in your house is not likely to be a problem.

The condition of aluminum electrical wiring connections vary greatly from house to house and even from branch circuit to branch circuit within a particular house. It is possible for very unsafe conditions to be present, but not visible, in any house with aluminum branch circuit wiring.

It is inaccurate and even dangerous for anyone to make any representation about the condition of aluminum wiring in a specific property without an on-site inspection.

Are the connections to the aluminum wire in any branch circuit safe? Without determining what types of connections are in the system and how they were made, nobody can answer the question definitively.

Are the receptacles “push-in” or “screw-terminal” type? If screw-terminal wired, how is the wire placed under the screw? (Does the wire go straight in or is it wrapped around the connector)? Are the screws steel or brass? Are the screws plated with zinc on the neutral side? What kind of splicing connectors exist in the system? If they are twist-on connectors (“wire nuts”), are they the live spring or restrained spring type? Did the installer clean the aluminum wire to remove the oxide before making the connection?

Were the spliced wires pre-twisted together? Was a proper corrosion inhibitor used on all connections?

Only after having the answers to all of these questions (from direct observations), can an evaluation of the relative safety of the wiring system be made.

These types of questions cannot be answered by a visual home inspection. Consequently, when a house contains any branch aluminum wire circuits, the client is strongly advised to have the electrical system thoroughly inspected by a qualified, licensed electrical contractor familiar with aluminum wiring.

 Bryan Freeman operates CanInspect HRM Home Inspection Service in Halifax.; Email [email protected]











  1. Thank you to all comments posted and the writer of this article, very good reminder of potential issues facing our clients.
    Brian, in my experience I do not believe realtors would give an opinion on aluminum wiring. In my experience almost all realtor would suggest the client ask an electrician.
    I think I mentioned this earlier and is worth repeating. A home inspection should be done by the seller when selling their home. If there are issues it gives the seller an opportunity to fix the problem. This way clients can negotiate stronger offers with less uncertainty.

  2. A few years ago I bought a home that had aluminum wiring. I had the wiring inspected and except for a few receptacles that had been altered by the seller was able to have the wiring certified. My problem occurred a few years later when I went to sell the house. I was always being low balled with the aluminum wiring as the excuse for dropping my pants to sell the house. Finally I hired a contractor to replace the aluminum wires with copper. It’s true the electrician costs were under $5,000 but the costs of removing and replacing drywall was both disruptive and costly. I finally was able to get a fair price for my house because it did not have the stigma of being a fire hazard. My mistake in buying house with aluminum wiring probably cost me $50,000 all in. Live and learn.

  3. Bryan,

    I am a journeyman electrician with a decade of maintenance experiance, and almost two decades as a realtor. You cannot inspect the terminations without disturbing the devices. It is impossible to see the condition of the wire without this step. There is no such thing as good aluminium wiring. Because alumunium has a property called “cold flow” ( it flows away from a point of pressure eg: being under a screw or quick connect”, it is never safe. Aluminum wiring must ALWAYS be changed to copper tails with approved anti corrosion compound on every device. The incidence of electrical fires on aluminium to copper is 47 to 1. The cost to have an electrician make these changes is quite small. An average house should take 3 to 6 hours. Advising anything other than replacing every device is irresponsible and dangerous. If the inspection shows aluminium wiring, the seller should pay to have the remedial work done.


    • Years ago I had a very expensive custom built home listed. It had been on the market previously and did not sell. It had been built in the 50’s and I was aware (in the 90’s) to be cognizant of some of the pitfalls relative to alum wiring.

      I very very rarely had a listing that didn’t sell, so I set about to prove what the owners believed to be true (orig owners who had the home built to specific standards above code in other instances). Just a couple of expiries I had in many many years. One was this house.

      I had Ontario Hydro from Toronto attend, arranged to have a special inspection prepared that the seller paid for, of course, that approved the wiring and stating that the aluminum wiring was done to code and they stated that the wiring should present no problems to a future buyer.

      Today I don’t think anyone in the hydro world would even attend the premises, perhaps. HOWEVER, no buyer would accept it. The listing expired. The following year, the property came on the market again. That time it did sell. So, once again, there’s a lid for every pot. Apparently someone believed all the hydro reports, eventually.

      The current problem remains: how to get insurance on these properties… that is often a struggle. I always wondered what would have happened had I been party to that sale and a fire occurred after the fact. Scared the socks off me, to be truthful.

      Another property in a lesser price range was of interest to buyers I had under contract. They chose the property to view, in this case, and I had to insist they put an inspection clause in. They really didn’t want one. I was aware that the whole subdivision was built using alum wiring.

      Oh, my! the things that inspection revealed about the alum wiring. The house DID NOT pass the inspection. My buyers were so disappointed, but fortunately I did sell them another place. They sooooh thought they were wasting the dollars spent on the inspection, and then had to pay a second time. The inspector showed how the wall receptacles were “hot-wired” and dangerous, with loose connections even. Even then the wife really wanted the house, but finally releases were signed, based on the inspection findings.

      Carolyne L

  4. Bryan:

    This is excellent information.

    Most Realtors will tell their buyer clients that aluminum wiring is OK (which as you know, the actual ‘wire’ is OK, properly installed, and has not been bent back and forth etc.) so long as the receptacle/switch etc. joints were initially screwed down tightly. Obviously, there is much more to it than that.

    This article should be forwarded to the educrats at ORE, to be taught verbatim to newbies and veterans alike…it is that important toward establishing credibility on the parts of Realtors in the minds of their clients.

    There are three electricians in my family (brother, brother-in-law and nephew), and my head just shakes when I hear some of the horror stories that they tell me regarding do-it-yourself wiring jobs that they have come across when homeowners have personally added wiring to garages, sun rooms, basements, small additions, finished attics etc., all without permits, and thus, all without proper inspections.

    One simply does not know what has gone on within the after-new-sales lathed over walls in hundreds of thousands of re sale houses out there. Thus, one cannot ‘ever’ categorically state that ‘any’ wiring is OK in ‘any’ re sale property, no matter how new the re sale house is.

    Speaking from the standpoint of an ex tradesman/ex assistant builder in my father’s new home construction business, many tradespeople take many shortcuts in efforts to make more money, especially within the new home project housing market. Tradespeople typically get paid a certain amount per house (after having had their low bids accepted for numerous houses by the builder) to complete the wiring, plumbing, heating etc., no matter how long these installations might take nor no matter what unforseen predicaments the tradespeople might run into (inclement weather, labour shortages, material shortages, material and labour price increases etc.).

    The above negatively created financial fallouts usually rear their ugly heads as simmering latent defects that bite owners in the pocketbooks down the road of ownership in the form of repairs, be they first time or subsequent owners.

    At sixty five years of age, and with a ton of construction experience behind me, I am not ashamed to say that I learned something from this expose’.

    Thanks Bryan.



Please enter your comment!
Please enter your name here