I had a question/concern. I have a 60 year old house that I recently
had the majority of the plumbing replaced on. The house is small with
just one bathroom/kitchen/spicket/utility tub to supply. This weekend,
I had everything replaced but the horizontal pipes, since they were all
in good shape and made the job much quicker/easier (cheaper). The
charge was only $1200 to install the new copper, and now I'm a bit
concerned after reading about connecting galvanized pipes to copper.
There are four spots where this was connected directly - the kitchen
(hot/cold) and the shower (hot/cold). The water main and the water
heater both have dielectric unions to prevent the materials from
Anyway, everything is working great and in most areas, the pressure is
noticably better. I've read in some spots that connecting the two
metals will cause the galvanized pipes to deteriorate quickly, even if
the entire plumbing system is grounded. I have seen several cases like
mine where the connection was done in the same fashion (directly), but
reading phrases like "rapidly speeds corrosion" has me a bit nervous
and wanting to just have the remaining pieces converted.
Any suggestions/input would be greatly appreciated.
After looking at photos online of different brass fittings, I believe
they may have. The only photos I had viewed before were of dielectric
unions, which they definitely didn't use..but brass is a possibility
not that I think about it. They screwed the fitting in to the
galvanized section and then welded the copper to the fitting..so
hopefully the fitting is brass..it looks pretty similar to copper and I
have no idea how to tell the difference visually, but I can't imagine
the brass fitting would cost that much more than copper to the point
that they would simply not use it. I will ask them tomorrow since they
are coming by to fix a slow drip. Eventually, I'll probably just have
the 4 remaining pipes replaced, but it seems somewhat common to just
redo the horizontal piping.
This is not correct. You won't have a problem with galvanic corrosion
between the copper and brass (anodic index difference of 0.05V), but
you will have a problem between the brass and the galvanized steel
(0.80V). An anodic index difference of 0.50V or less is recommended in
a controlled environment (like a house) to avoid corrosion.
In theory, you can have accelerated corrosion at the junctions, but I
wouldn't worry about it too much.
I've taken some piping out on rehab jobs that were pretty old, and the
corrosion wasn't a big deal.
You could check the joints in ten years or so, and if you see anything going
on, you can always
change out to dielectrics then. The galv pipe is more likely to fail first
due to calcium clogging.
Just my own experiences, but the previous owner of my house repaired a
section of galvanized with copper. The copper fittings corroded much faster
than the galvanized did and in fact failed after less than 10 years. Now
there are a lot of factors there, such as the quality of the work, the
quality of the pipes, etc however I couldn't mistake the massive corrosion
at the junction.
Get the rest of it done when you have the chance - otherwise it will
eventually fail (10 years, 5 years, ???)
Thank you to everyone for the input. I actually had the plumber
complete the job when he was out here for a quick fix on the utility
tub. $200 for about 2 hours of work, but the entire house is now
completely done and my anxiety has finally returned to normal. Better
safe than sorry, it certainly isn't worth the worry for $200 since I
plan (hope) to sell in 2-3 years. In a buyers market like this, I'd
have to have something small like that be a deal breaker when the
remedy is/was fairly easy.
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