Aluminum wiring in a home?

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powerplay

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For older homes with aluminum wires, is it worthwhile tearing apart drywall to replace with copper cables? Insurance is ok with proper splicing technics with copper tails and wire nuts for the purpose of aluminum to copper so I assume it is a a safe compromise, but would love to hear feedback of any post inspection issues if any?

Thanks again,
Powerplay!
 
powerplay said:
For older homes with aluminum wires, is it worthwhile tearing apart drywall to replace with copper cables? Insurance is ok with proper splicing technics with copper tails and wire nuts for the purpose of aluminum to copper so I assume it is a a safe compromise, but would love to hear feedback of any post inspection issues if any?

Thanks again,
Powerplay!
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Why not fish walls instead? Unless finishing drywall is a hobby of yours.:cool:
 
I lived in a house with aluminum wire. I would not replace it but I would make sure it is installed/terminated properly.
 
Dennis Alwon said:
I lived in a house with aluminum wire. I would not replace it but I would make sure it is installed/terminated properly.
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The products available today make the remediation a lot easier/safer and thus preclude the need to replace the wiring method. Remember, it is not the aluminum wiring that is the issue, it is the termination of the aluminum wiring that may create the issue.
 
Generally aluminum wire is not a problem as long as it is terminated properly, that where the problem is, we have a subdivision that all the houses are done in aluminum NM, and while it was a great service call area, I have done a few retro fits to some to re-do all connections, basically leaving the cable in place but making sure all connections are done to spec.
Here are some pointers when dealing with aluminum:

As said older aluminum will corrode, so using wire nuts with the dielectric grease in them will prevent this as well as allow you to change from aluminum to copper, Ideal DB twisters are such listed.

Aluminum expands much more then copper, and if put under just a set screw brass or copper terminal it will cold flow as it expands and will loosen when it cools off,
where terminated in a pressure type connector, make sure the connector is a pressure plate or has the spring type washer or plate under the set screw, it is important to only tighten the connection to the listed pressure, or you will cause the aluminum to cold flow out, breakers with aluminum terminals with set screws should be ok, but make sure it's not just plated copper as some are, anywhere else change over to copper wire before termination.

When hitting receptacles/switches with brass screws, use the twister aluminum to copper pigtails, or replace the receptacles with clamp type plate terminals, use plenty of anti-oxidant, at all connection, or a good dielectric grease, the latter doesn't dry out like anti-oxidant can.

Almost all failures of aluminum wiring can be explained in improper terminations and connections, some failures are because of the conductor being nicked when stripping, it is imperative to make sure to not nick the aluminum conductor when stripping, I will use one wire size larger then the conductor and pull off the insulation with my linesman,, I have yet to have a call back on any of these houses that I done, and the home owners are amazed at the money I saved them from doing a complete rewire, for the most part as with copper I have only seen a very few times where the wire failed in mid run, and even then it was attributed to rodents such as squirrels or mice.
 
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Aluminum has gotten a bad rap over the years, most of the failures I've seen is where someone has spliced copper directly to aluminum. Especially mobile home services where they would double lug a #10 copper with a 4/0 aluminum to run a well pump.
 
Aluminum expands much more then copper, and if put under just a set screw brass or copper terminal it will cold flow as it expands and will loosen when it cools off,
where terminated in a pressure type connector, make sure the connector is a pressure plate or has the spring type washer or plate under the set screw, it is important to only tighten the connection to the listed pressure, or you will cause the aluminum to cold flow out, breakers with aluminum terminals with set screws should be ok, but make sure it's not just plated copper as some are, anywhere else change over to copper wire before termination.

When hitting receptacles/switches with brass screws, use the twister aluminum to copper pigtails, or replace the receptacles with clamp type plate terminals, use plenty of anti-oxidant, at all connection, or a good dielectric grease, the latter doesn't dry out like anti-oxidant can.

Almost all failures of aluminum wiring can be explained in improper terminations and connections, some failures are because of the conductor being nicked when stripping, it is imperative to make sure to not nick the aluminum conductor when stripping, I will use one wire size larger then the conductor and pull off the insulation with my linesman,, I have yet to have a call back on any of these houses that I done, and the home owners are amazed at the money I saved them from doing a complete rewire, for the most part as with copper I have only seen a very few times where the wire failed in mid run, and even then it was attributed to rodents such as squirrels or mice.[/QUOTE]

Can you please explain what cold flow means.:confused:
 
earlejohnson said:
Can you please explain what cold flow means.:confused:
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When aluminum is under a terminal that doesn't expand at the same rate as the conductor such as a copper terminal, it will try to expand larger then the terminal, this results in the aluminum flowing out because it cant expand to a bigger diameter and when it contracts after it cools off it will no longer be a tight connection.

Kind of the same results if you over tighten down on aluminum wire till it smashes the wire, the wire that is smashed will flow out of the terminal, now loosen the set screw and you have the same effect.

Aluminum terminals don't have this problem as they expand at the same rate as the aluminum wire, but they can loosen up on a copper conductor if they get hot since the copper doesn't expand as much as the terminal, but since you can tighten the terminal a little more on copper it doesn't cause as much problems, and that there is a small amount of springiness to the terminal when tighten to the proper torque, just not the other way around with a copper terminal and aluminum wire.
 
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ptonsparky said:
We find a lot of cu mixed under lugs with al. Those that have had a corrosion inhibitor applied seem to work ok. Just an observation. Not a recommended practice.
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If there isn't much load on the circuit- no heating then it may work forever. Years ago I used Buchanan wire nuts to splice alum. to copper. The mfg. said it was rated for it but eventually lost that rating. I bet most of those connections are fine however, Like you said, it is not good practice. I would bet if you did that on an electric heating system the results would not be good.
 
What kind of cracks me up is that we do not hear too much about the termination failures of copper. There are many, many failures with copper as well. Any installation that is under a load, and not properly terminated will eventually fail. Aluminum has the "rep" that some people cannot seem to get past.
Most installations properly performed will be just fine, regardless of copper, or aluminum, or brass, or copperclad, etc....
 
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