Aluminum House Wiring

Aluminium has a bad habit of corroding at connections. I would advise removing it.

AH is spot on regarding the expanding and contracting. This is the main reason aluminum wiring has been banned in the USA for homes. After a few years, the wire is no longer tight under the screws. Open any wiring device in a 30 year old house and you will find dirt, insects, dust, etc. inside. Add a loose connection to this debris field and the skyrocketing possibility of an arc can turn the house into charred lumber along with the occupants. Most people with aluminum wiring still in their homes either hire an electrician, or themselves open every outlet, switch, and fixture every 2-3 years and tighten the screws. Me...I'd replace the wiring.

I agree with TonyS, I would get rid of the aluminum wiring also.

Can you use this as a price negotiating tool?

In other words, ask the seller to drop the price to compensate for the replacement of the aluminum wiring.

Having been a licensed home inspector in a previous life, defective (or perceived defective) items can sometimes be a negotiating factor in the final price.

Is the aluminum wiring legal per the city/county electrical code?

Have you hired a home inspector? It is often times better to shell out the $300 to $400 to hire one.

Good luck with the house hunt!

Forget the home inspector. We hired a home inspector that gave our house a clean bill of health. It is nothing more than a shack on flat 2.25 acres with mountain views on the end of a dead end road. Perfect location, house is unliavable. So forget the inspector.

Re-wire the house with copper or hire an electrician to re-wire the house.

The issue of aluminum house wiring is that the aluminum expands and contracts with temperature and some alloys tended to corrode and oxidize at the splices and junctions. This causes contact resistances to build up and increases the potential for failure.

Aluminum was used for its cost and weight savings (mostly in multi-story dwellings where pulling high amperage cable is a factor) and was popular in the 1960s and 1970s. In 1973 some things changed after a number of electrical fires were traced back to aluminum wiring. I think it was the aluminum type. I do not know if your local code supports aluminum wiring (most will not allow wires of less than 6 AWG in aluminum). If not, any changes made to the building that require alteration of wiring that is aluminum will mandate that the wiring be pulled and new wiring that meets code installed. This can greatly increase the cost of a renovation.

Please check local codes to see if it is still in use in new construction.

Worst case failure mode for aluminum can be a fire, but several other things need to be present for that to happen. Nevertheless, a failing contact point could arc, which is the source for a fire if a suitable fuel source is available (i.e., spiderwebs, mouse nesting material, etc.) at the point of arcing.

My personal opinion is I do not like it.

Any home that your son considers should be inspected by a qualified home inspector and in this case if you could specifically hire an electrician to pre-inspect the home wiring it would be a bonus.

And I totally agree with the remodeling / addition problem. If your son wants to add on a room in the future or remodel the kitchen or baths, he will face a daunting expense because in most cases the inspectors will not allow connecting new copper wiring to existing Al wiring. So the first remodel will entail at the very least replacing that entire circuit back to the panel.

I agree with Jraef. It would be EXTREMELY expensive to rewire the whole house with copper. My nephew bought a house several years ago that was built in the early 70's and had aluminum wiring. Being an Aerospace Engineer (yes, I worked on the Shuttle Main Orbiter Body engine and fuel supply system design in the early 70's so I am a rocket scientist - whatever that is) and the family repairman/troubleshooter so it fell to me to check the wiring out and make corrections as needed. I checked every connection at wall outlets, light switches, etc. I found no corrosion, loose connections or signs of over heating. It appeared that nothing had been touched for over 37 years. I cleaned all the wire ends, applied anti-oxidant paste at every connection and re-torqued the screws. I also made sure that every outlet receptacle, switch, etc. was rated for both copper and aluminum. If you want more security there are fasteners available that are swagged onto the end of the aluminum wire that virtually eliminate any corrosion and chance of an over-heat condition. The connectors are a proprietary design and are available only to licensed electricians who have gone through the company's training course, been certified and are franchised to install the system. Obviously this is significantly more expensive than the clean, paste and re-tighten process. It is still significantly less expensive than tearing out the aluminum wire and replacing it with copper.

JRaef; right on! there is nothing wrong with aluminum wiring, its the terminal connections that are the problem, U.L. screw up with approving devices for aluminum use, this was a big source of many service calls. Geaycov has the real issue. perry

Thanks for the comments so far. Since we are still in the looking process, he hasn't committed yet to a house. As several of you had suggested, he would certainly need a house inspector to look at the entire structure and support services before making a final committment to buy (I've identified severla deficiencies that can be repaired for relatively low cost - some rotted siding, rework of back yard pavers to eliminate low spots, etc.). My thought was to also contract with a local electrical contractor/electrician for a couple of hours labor to look at the wiring (not to be too pessimistic on house inspectors but my experience with them has been hit and miss as they are more general - I know there are several outstanding ones out there - but many have a more specialized background and are only familiar with "generics" of other categories). For something as critical as a potential wiring issue, I would prefer to utilize someone that is familiar with electrical codes, etc. such as a licenced electrical contractor, at least for a more knowledgeable opinion on the subject matter. Any findings would definately be used as a negotiating point for the house, I'm trying to get an order of magnitude cost to rewire from a couple of contractors that I have used for plant projects in the past, I'm guestimating somewhere around the $10K mark but could be way off. Anyway, thanks for your continuing comments.

We have a 35 year old house in the desert which has Al wiring supplying the oven with power. It has never given us any problems.

Corrosion and thermal expansion/contraction are indeed things to consider. Since it seems that lots of houses around there have Al wiring, someone should have some "local knowledge" if the wiring has problems.

Have it thouroughly inspected if you do decide to buy. Check with your insurance company, too.

Good luck.

This site has a lot of pertinent info and links.

As far as I know, where I live, there are no code requirements to remove existing AL wiring in older homes.

Another thing to look out for is the polybutylene water piping, which is no good.

You say "some aluminum wiring". Where, exactly? My house (built in 1979) has copper wiring except for the service entrance, which is aluminum.

If it's only the service entrance that's aluminum, that wouldn't be terribly hard / expensive to replace.

On the other hand, I guess that is (was?) still allowed (in 1979) because it is apparently, well, something--easier to inspect, easier to make sure it is done right, with the right anti-oxidant materials, suitable (Al-Cu) terminals, etc.

I'm not worried about mine.

It's a one story house. So far, I found aluminum at receptacles in each room (BR, LR, Kit, Baths, garage). About 3/4 of the basement is finished and appears to be copper in the "new" area - evidence of newer style breakers in panel and copper at the receptacles (at this point I'm assuming that they ran new lines from the breaker panel versus tying into aluminum but won't know for sure until inspection and cover of electrical panel is removed). The unfinished area with furnace, hot water heater, and hookup for washer and dryer has at least 1 receptacle that is aluminum supplied. Ther eare a couple of ceiling fans in rooms, not sure how they are hooked up and if fan connections are rated for aluminum or not.

I should note that my house (circa 1994) has 2x200amp 120/240v services (cheaper than a single 400 apparently) run with copper throughout the house. I have a 100A sub panel in the garage for tools. The conductor between one of the 200s and the 100 is aluminum, no issues since installation. One interesting point is that a couple of times a partial power interruption occured (some of the power stays on in the house while some goes out - I guess only one leg of the incoming goes out and they ran the second panel off the 3rd leg?).

I once owned a house (1973) with aluminum wiring and would also recommend changing to copper, no matter the cost. The hot water tank was electric and the breaker on the bus bar caught fire twice. That is the spot the arcing occurred when there was demand for heat (off/on cycle) in the tank. It was the plastic breaker (Sylvania commander) that actually burned as well as the wire coating inside the panel. The breaker did not flip as expected. I was lucky to catch it both times as my panel was located in an attached garage. The wiring from the panel to HWT was changed to copper and I sold this house as quick as I could. The new owners were also warned and the house still stands today. Aluminum is now banned but there was that brief window when builders could use it.

I agree with the poster who recommend that you negotiate the change in the sale. If your eldest son buys the house change the wiring.

Aluminum wire does corrode. However, they make a lubricant designed to prevent this from happening. Check to see that some has been applied. If not, lubricant can be purchased at Home Depot or other building suppliers. Aluminum was mostly used for main line coming into house. Wire size should always be rated one wire size higher than copper.

I was an Electrician for 31 years and rewired many homes and some apartments, after they burned. Never wired one before a fire because no one inspected the wiring before buying. Very good you found out. I would not live in a house with aluminum run for outlets and lighting!!! Pass on this deal or get the price down to cover costs and get it rewired!!! The NEC (national electrical code) lets you install aluminum for anything using 50 amps or more, smallest is #6 awg. Electric ranges, air conditioners, panel feeds, etc. Check with the building department in your area, they may not allow aluminum at all.

Aluminum wiring is not as bad as people make it out to be. I am an electrician in Texas and my house has aluminum wiring. The house was built in 1972 and I have had zero problems with the wiring. Aluminum wiring expands and contracts at a different rate then copper. The issue is when you change out plugs and receptacles. This is the area that causes problems. Since aluminum expands and contracts at different rates you have to make sure any plug or receptacle you change is rated for use with aluminum wiring. The correct plugs and receptacles will be marked with CO/ALR showing they will work with both aluminum and copper. Anything not rated for use with aluminum will cause a problem in the long run. Aluminum wiring is capable of carrying a load just as well as copper if not better. There are ways to pigtail copper to aluminum if that is what you would want to do, that would allow you to use any plug or receptacle on the market. Check out ALCOPSTORE.com for the correct do-it-yourself connectors when pig-tailing copper to aluminum. Be proactive with aluminum wiring and you will have no problems.

Jamesw is right on the mark. I have lived in an aluminum wired house since 1968. It was a new build in a development and I quickly learned that aluminum wiring was an issue since I was in engineering construction at the time. The main problem was that the electrician didn't used the oxide paste or Colar plugs and switches. I first went around using the paste as I tightened up the connections. The swagging tool was too expensive but an electrician told me that if you pigtail a copper lead from the aluminum with a wire nut the expansion contraction issue at the fixture was prevented. Eventually I replaced all the older fixtures with Colar plugs and switches and replaced all the wire nuts with the more expensive but approved for that use Blue aluminum wire nuts. Having replaced a burned receptacle or two it is nothing to take lightly but replacing all the wiring is really overkill. Inspecting all the receptacles and switches is a must and making sure they're OK is a must do. Most overhead lights and fans are wire nutted anyway and do not pose as much of a safety issue.

I personally don't mind Al. I am an electrician for 10 years and an electrical eng. for 1 :).

Aluminum was never issue, believe it or not copper is the criminal in this case.

Aluminum & Copper have different expansion coeff. results in over time, the wiring losing up on the plug/switch & lighting the place up (no bun intended).

Here are your options, which I think was mentioned at one point or another:

1) Rewire the house (6-10k including service) note this does not include the million holes u will have to patch in your walls :D

2) inspect the home from a good electrician (they are far n few) and replace all copper receptacles / switches w/ special designated aluminum devices. WRT the lights, just make sure it is a good connection and stick some anti-oxidant on it. Check main panel/breakers that they allow aluminum wiring, if not. Creating a pig tails saves buying additional breakers.

3) Don't buy.

Happy hunting, just got a good home :) all aluminum , build 1972 :D. Planning to rewire as a get going with renovations.