I put in an offer on a house last week (one with enough room for all my
tools!). One of the conditions was insurance. I have run into a little bit
of a problem. My Insurance company wants an electrician to certify in
writing that everything is "safe".
Anyone know how I get this done? The offer clock is ticking...
Who has had problems with their insurance agent with regards to aluminum
wiring, and how did things work out?
That's overstating the case a little bit. Properly installed and maintained,
aluminum wiring isn't substantially more dangerous than copper. The big
problems with aluminum are that properly installing and maintaining it *is*
substantially more difficult than doing so with copper, and that IMproperly
installed and maintained aluminum wiring is a hell of a lot more dangerous
than improperly installed and maintained copper wiring.
Having said that... given the choice between two otherwise identical homes,
one wired with aluminum and the other with copper, I would unhesitatingly pick
the one with copper, unless the difference in price were sufficient to
compensate for the expense and hassle of replacing the aluminum wire.
But that's mostly because I've seen the kind of dumbass things homeowners do
with their own wiring. If I knew that the aluminum system had been installed
and periodically checked by a pro who knew what he was doing, and never
molested by anyone else, I believe I'd rather have that than a copper system
that had seen three or four decades of mods by clueless homeowners.
Just the same, while it's always prudent to have a sufficient number of
working smoke detectors in any home, it's probably more important if the
wiring is aluminum.
Doug Miller (alphageek at milmac dot com)
Around here, you are required to disclose any defects or banned use
materials such as Ureaformadahyde foam or aluminum wiring and any
other major defects. Aluminum wire was in general use about 35/40
yrs ago and quickly fell out of favor because of the overheating/fire
The wire itself is not at issue. It's the possible splices into it
and the devices at the end of each run. The lamp sockets and wall
plugs use brass screws that cause the problems when electrolysis
occurs and over time wires become loose under the screws - high
resistance = hot spots = fires.
There is a low temp aluminum solder that will join aluminum to
copper/brass, enabling you to install copper pigtails at each junction
box, outlet box, etc. It's an Alladin product, comes in a small
vial (like a pill bottle) all coiled up with a wee tiny bottle of
flux. Use sparingly and heat with a propane torch. What works here
may not work there (where you are). Check with your electrical guy
about possible fixes and the costs.
You got some very good advice in another post. Call up a local
electrician and get his best opinion.
Good advice. Here in Texas they're licensed, which generally makes for a
Even then there is often some CYA involved, so you must still have the
knowledge to separate the wheat from the chaff. I welcome third party
inspections of new homes, but always inform the prospective buyer that there
will likely be some items which will be subject to discussion and not
Although I never tried I can't imagine an electrician certifying that
a home's wiring is 'safe'. They may be able to check that it was
installed correctly and pull the outlets & switches to check the
connections and make sure proper fixtures are installed. What they
can't do is check every connection in the house without tearing into
the walls. The Al wire has a high failure rate at connections and
stress point (bends).
Read here for more info:
If you don't have to have the house I would pass on the deal.
I have been reading this thread and started wondering if all of this discussion
applies to the service feed into the house. My 20 year old house has a 125A
service from the street that is aluminum.
David F. Eisan wrote:
> I put in an offer on a house last week (one with enough room for all
> my tools!). One of the conditions was insurance. I have run into a
> little bit of a problem. My Insurance company wants an electrician to
> certify in writing that everything is "safe".
> Anyone know how I get this done? The offer clock is ticking...
> Who has had problems with their insurance agent with regards to
> aluminum wiring, and how did things work out?
Having been directly involved in the electrical industry during the
big bru-ha-ha involving aluminum wiring for residential applications
some 30 years ago, I'd probably do one of two things:
1) Walk away.
2) Deduct $50K to cover a rewire.
The stranded Al wire doesn't have the same propensity for failure as
'solid conducter' Al, I'm not a physicist so I don't know why. It is
still very common to use stranded Al for dryers, ranges and AC units.
And most, if not all, of those transmission lines running over your
head are Al.
I beLIEve the NEC has no prohibitions against solid conducter Al
branch cicuit wiring but some regional and local codes do.
> The stranded Al wire doesn't have the same propensity for failure as
> 'solid conducter' Al, I'm not a physicist so I don't know why.
It has to do with what is known as "cold flow".
When you make a connection using solid conductor Al, you have a good
solid mechanical connection; however, the Al oxidizes which increases
When current flows thru the wire, the Al wire heats up slightly and
the Al wire softens slightly and begins to flow or ooze, thus reducing
the amount of clamping force provided by the termination which causes
increased electrical resistance.
Increased resistance causes increased "cold flow" which causes
increased resistance, etc, etc, ultimately leading to the wire
melting, and then a fire.
BTW, the wire usually melts about 2"-4" from the termination, usually
up inside the insulation. Don't have a clue why.
There are many variables to the above process, so the amount of time
req'd varies greatly.
Infrequently used circuits may not malfunction for many years, perhaps
never, but you never know.
Stranded Al cable OTOH, uses special terminations, potted with "sheep
dip" to prevent Al oxide from forming, and special crimping tools to
insure a good termination.
It is a totally different world, but the increased termination cost is
quickly recovered by using lower cost Al vs copper for large cable
Same can not be said for small, 30A max, branch circuits found in a
home, for example.
I suspect that large amounts of current which will cause aluminum cable to
jump will cause loose connections also. Years ago I was using a set of
aluminum cable jumper cables to jump start a car. Every time the other car
cranked, the cables would jump and get warm.
You are confusing two different phenomena.
Cold flow refers to the tendency of a material to deform under mechanical
stress. Period. This is unrelated to the cyclic expansion and contraction due
to temperature changes as electric current is applied and removed. Cold flow
will occur in any overtightened connection, even if current is never applied.
Cold flow is a particular problem with aluminum wire because the stress levels
required to produce cold flow in aluminum can be readily achieved with hand
tools. Proper tightening of lugs with aluminum wire requires the use of a
torque wrench calibrated for torques measured in inch-pounds (or, of course,
the metric equivalent). Any overtorqued connection will loosen in time as the
material flows away from the stress.
Aluminum and copper both expand and contract as they are heated and cooled.
Aluminum, however, does so to a much greater extent than copper, and an
*under*torqued connection will *also* loosen in time due to this effect. You
correctly noted the increased resistance that results from the oxidation of
the surface of the aluminum. It should also be noted that this is not a
problem with copper wire, because copper oxide is a conductor of electricity.
Not quite as good as metallic copper, but close. Aluminum oxide, on the other
hand, is a semiconductor.
Doug Miller (alphageek at milmac dot com)
I wouldn't walk away, I'd run as fast as I could. There were a few houses
wired with aluminum in our area back in the 60's but they soon made it
illegal to use the stuff.
I never owned a house wired with aluminum but have had houses that
have had aluminum drops from pole to house. My previous home had to have the
special aluminum to copper connectors replaced every 3 or 4
years as they would burn out.
We moved several years ago to a 50 yr old house that had the old screw in
fuses so we had a new 200 amp panel installed. When the power company came
out to install a new heaver aluminum drop they did not
use the special aluminum to copper connectors as they had in years
past, they used husky u-bolts to connect the aluminum drop to our
copper line, said the old connectors were too troublesome. RM~
size=1>...<BR><BR>> Where are you from Rob? Around here (northeast),
everything is aluminum<BR> from the pole to the main breaker.
<<BR><BR>Guess I didn't make myself clear. That's the way it is here (Tulsa), they<BR>use aluminum drops to the panel but can't go past the panel. They (power co)<BR>quit using the special aluminum to copper connectors due to their
<DIV><FONT size=1>They quit using aluminum inside of houses years ago. Not real
sure how long </FONT></DIV>
<DIV><FONT size=1>they did allow it but it wasn't for a very long period of time
back in the 60's.</FONT></DIV>
Unfortunately, my parent's house, which was built in the mid-60s, has
all aluminum internal wiring. The dining room has started to fail in
parts, the light switch to the ceiling lights doesn't work anymore, I
ran an extension plug for the lights to an independent outlet so my
mother can get light but really, the whole house needs to be
completely rewired with copper.
I'm just afraid that I'll get tapped for the job if I suggest it. :)
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