Post by Pat Auriol.
Over 7,000 homes in Mississauga contain aluminum wiring. Extended this across the provinces and we are looking at tens of thousands of homes. If the subject dwelling was built between the mid-1960s and late 1970s, there is a strong possibility that aluminum wiring may be present. Is this a cause for worry?
The short answers are both yes and no!
No, because, with all these tens of thousands of homes we don’t see them burning down in their droves, Yes, because there is a real and present risk. We will expl,ain more here.
Differences between copper and aluminum wiring
Apart from the color both are metal and both conduct electricity. Aluminum has more resistance to electrical flow than copper, with only 61% of the conductivity. Because of this, a wire made from aluminum needs to have a larger cross-section than a wire made of copper carrying the same electrical load.
Aluminum is much lighter than copper at only 30% of the weight, so even if a larger size of wire is needed, the resultant cable is generally much lighter for aluminum.
Aluminum is softer than copper and has a great rate of expansion and contraction when heated and cooled. Copper also has a greater tensile strength so is less prone to thinning when it is put under strain lengthwise.
There is only one type of metal used in copper wires, copper. Aluminum wires are made up of an alloy, which is a mixture of two or more metals. Two types of alloy are found in residential wiring, types AA-1350 and AA-8000.
AA-1350 has a minimum aluminum content of 99.5 percent AA-8000 has a lower percentage of aluminum content and was designed to more closely resemble the properties of copper for wiring. AA-8000 is the only allow allowed to be used in modern wiring.
Residential wiring
In the 1960s and 1970s, due to the high price of copper relative to aluminum, the AA-1350 grade of aluminum began to be popularly used for household wiring.
Aluminum wiring itself is safe but requires special handling, connectors, and periodic inspection.
As we said previously because aluminum has different physical properties than copper the two react differently and expand/contract differently when under electrical load. Improper connections and/or use of incompatible materials may cause the connections to become loose resulting in sparking, arcing, oxidation and heat build-up and finally, the possibility of a fire through the ignition of surrounding combustibles.
Aluminum wiring may be something to be concerned about for 3 basic reasons:
- The wire can overheat at the receptacle due to it tends to oxide thus increasing the wire’s overall resistance.
- Aluminum can be easily nicked because it is softer than copper.
- Aluminum can thin and therefore provide greater resistance if pulled lengthwise.
- Aluminum wiring also tends to change shape due to thermal expansion and contraction. When this happens, the screws can become loose or fall off at the terminal itself.
Unsafe aluminum wiring warning signs
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Aluminum wiring requires the use of specific type components and special handling techniques. It is very popular to replace old/outdated receptacles and switches when preparing the dwelling for sale or deciding to update living areas – i.e. “Decora” style components.
These are visually more appealing than the old fashioned components and the folks at local building supply stores are more than happy to sell them to you.
What is “sometimes” (ok, usually!) left out of the discussion is that: These are not aluminum compatible components!
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Some Things to Consider:
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This is not only of great importance for the occupants’, current or future, safety but may help avoid challenges in dealing with insurance providers.
Editors footnote:
As Inspectors, we are frequently taken to task by the uninformed Realtor, or ticked off electrician. The Realtor is concerned because they think we are making a mountain out of a mole-hill and that our reporting of the concern will lose the sale (and their commission). Infrequently, we will get a call from an irate electrician who inspected the home themselves and says everything is “OK”.
If you find a concern and you are sure of your diagnosis, stick to your guns. Call it. Don’t back down until you are provded to be incorrect. Some Realtors (the bads ones) and some Electricians may try to use their “years of experience” as a reason for suggesting you don’t know what you are doing.
Here’s an example.
We recently inspected a home built in the “Aluminum years”. Sure enough their was aluminum wiring.
The report identified that aluminum wiring was found, and we inserted our usual pre-built “Aluminmum wiring” narrative.
“This property was found to have aluminium wiring.
Property owners today are finding many insurers may not provide or renew insurance coverage on these properties unless the wiring is inspected by the Electrical Safety Authority (ESA), repaired or replaced as necessary, and a copy of the Certificate of Inspection is provided to the insurer.
You should check with your insurance company for their requirements.
If repairs are required, remember that if you’re hiring someone to do electrical work in your home, by law it must be a Licensed Electrical Contractor. It is recommended you hire one familiar with aluminum wiring. Before making the repairs, the Licensed Electrical Contractor should do an assessment and take out any necessary permits so the work is subject to review and inspection by ESA. Be sure to obtain a copy of the Certificate of Inspection for your records.
Myths and Facts about Aluminum Wiring
Myth: Aluminum wiring was recalled because it is known to be a fire hazard.
Fact: Aluminum wiring itself is safe if proper connections and terminations are made, without damaging the wire, and any devices used are approved for use with aluminum wire.
Myth: Aluminum wiring is no longer used for interior wiring systems.
Fact: The Ontario Electrical Safety Code (the Code) permits the installation of aluminum wiring. It may still be used today for interior wiring systems in residential homes, as well as other structures such as large commercial and industrial feeders. Electrical distribution companies use it widely throughout their distribution systems as well, including the supply service cable to most residences.
Aluminum wiring can be used as long as proper connections and terminations are made in accordance with the Code and the manufacturer’s instructions.“
The home however also had Decora receptacles throughout. So we added to our standard narrative:
“This property has Decora fittings which ARE NOT CU/AL compliant. The circuits checked were not pigtailed. A qualified electrician should inspect and repair as required. Please budget for the costs of this work.“
Not long after delivering the report, we got a call from the listing Realtor who said that their was nothing wrong. He had spoken to “his electrician” who had told him that there were two types of Decora receptacle, ones that weren’t OK, and for an extra $5 more ones that were OK. He said the OK ones had been fitted.
Of course, this was total BS. I have had occasion to contact Leviton in the past to ask about the Decora receptacles. They confirmed, no such thing as a Decora CO/ALR or CU/AL receptacle.
So the Realtor had his electrician call me. He said “It’s OK, we looked at the home and all the receptacles were OK, they’d been pig-tailed with copper.”
Unfortunately for this electrician, I was following the CAN/CSA A770-16 Home Inspection Standard.
Section 5.7.4 states:
“Lighting,switches,receptacles,and junction boxes, including in each room, attached garage, and the exterior, shall be inspected. The inspection shall include, but not be limited to, an examination for
a) improper location;
b) improper function;
c) the absence of necessary equipment;
d) non-functional lighting, ceiling fans, and switches;
e) inappropriate switch locations; and
f) safety issues. “
We consider installation of a decora GFCI receptacle that supplied a sump pump to fall fould of at least three of those criteria so we donned our PPE, used the prescribed tools, powered off the recpetacle at the breaker panel and carefully popped the receptacle open.
Oops! GFCI on a sump pump. Damp location, no moisture protection, aluminum connection directly into receptacle, no pigtail.
When confronted with this, the electrician stated “We may have missed that one”
At which point, an ESA Inspection was demanded after proper repairs had been completed, and the home checked throughout.
The sale went through. The clients were happy (and safe). The electrician made money. The realtor got their commision.
And their was no need for any of this had they just trusted the qualified inspector and followed the recommendations in our report.