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Re: [TowerTalk] copper pipe for ground

To: Red <>
Subject: Re: [TowerTalk] copper pipe for ground
Date: Wed, 12 Jul 2006 20:15:08 -0500
List-post: <>
(Red: most of the time, my posts don't show up on
the list, reasons unknown, please forward this to the
list for me if it doesn't. Thanks)

On 12 Jul 2006 at 17:39, Red wrote:

> Lightning may have been incidental to the pinhole leaks.  The water in 
> some communities slowly corrodes copper pipes and causes pinhole leaks.  
> I believe it is a result of acidic water, but I don't remember for sure 
> what compound or ion in the water attacks the copper.
> 73 de WOØW

I locate water leaks for a living, all day, 5 days a FL.

Yes, water chemistry is responisble for the vast majority of leaks,
But, relative to the below questions... YES! Lightning absolutely
DOES cause numerous water leaks. Usually in the form of a
hole where it either arcs over to reinforcing mesh or rebar, or
else it makes less dramatic holes where "apparently" it discharges
into the soil. As most of us are probably aware, either the cold water
pipe, or possibly both cold and hot, are commonly tied to the
ground/neutral at the breaker panel. In 15 years of doing this, I
can think of only one instance where it was apparent that lightning
struck a hose bibb on the outside of the home as means of getting
into the plumbing... other than that, in most cases it seemed to
me that the lightning came in via the electrical mains. Of course,
that's not scientific, but it IS my opinion based on experience.

All "reasonably modern" homes plumbed with copper hereabouts
are plumbed with "soft" copper, i.e. copper that comes in rolls 
rather than straight sticks, with the connections all being made
at above ground manifolds concealed within walls, the idea being
specifically to avoid any underground solder joints.
I've never seen or heard of a solder joint failing due to a lightning
strike. FWIW there are still a lot of "hard copper" plumbed homes
with the joints underneath, and I've seen any number of leaks at
solder joints in them, but not directly attributable to lightning strikes.
Of course, you can't melt solder joints in a pipe full of water anyhow..

FWIW I did have one customer whose home took a lightning strike,
with the leak making itself evident in the form of loss of pressure,
along with a high flow rate at the water meter... it was due to a
PVC pipe in the yard rupturing, not from the strike, I suspect, but
rather a huge spike in pressure when the water in the copper lines
in the home was suddenly heated. Again, that's not scientific, but
that's the way it appeared to have happened.

"Most" homes here are now being plumbed with CPVC due to the
effects of the water, and there are rumblings about changing the
building codes to eliminate the use of copper. Other than that, it
seems to depend on whatever the architect specifies.

On the other hand..... I have reason to think that the ground/neutral
coming off the pole is not always at "zero volts" relative to ground, and
I therefore have to suspect electrolysis is at least partially behind
"some" leaks... and I don't know who the genius was that decided
that plain ol' rebar was acceptable as a ground rod at the meter,
but tying dissimilar metals together with wires just *can't* be a good
thing, either... and I doubt a rusty steel rod is particularly effective
at anything, let alone keeping a strike out of good old copper pipes
buried the length and breadth of a home.


> K4SAV wrote:
> > I can't confirm this first hand, but I have heard reports of lightning 
> > producing pin hole leaks in copper water pipes. Does anyone have any 
> > good data on this? Maybe the problem ocurrs ar the soldered connections?
> >
> >>Jerry, K4SAV


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