Copper corrosion

[bool_15]

I'm seeing some of my copper fittings and pipes have green/white corrosion. How to prevent them? Does it need to be replaced?

 

[SHEPLMBR]

Has it always been like that or something you just noticed? Just looks like a messy soldering job to me where someone did not wipe off the copper when done.

 

[bool_15]

It's 30+ yo house. I didn't inspect before but was just under my crawlspace to replace some shut off valves and noticed it then. I see some green and black spots in the copper.

 

[Geofd]

The copper may be touching another metal or the copper coating on the hangers is gone
I have also seen chemical vapors cause discoloring

 

[breplum]

The green is residual flux that was not wiped. Likely nothing to worry about.
The whitish on top of the solder is a chemical thing I've seen, probably further flux residue, and nothing of concern.

 

[fixitron]

You might also see some occasional green on the surface of copper pipe, often from the water of condensation reacting with the copper. Not to worry about it unless you see a lot of green at a fitting, which could be a very slow leak.

 

[plumbob61]

Good info above, look like a residential waste line if so not under pressure which is good. That flux corrosion could cause a slow leak eventually. You may want to just check it every so often. Side note if you are in Puget Sound area your house was probably built in the sixties, that was the brief window we were using copper on residential drain lines. In my experience it has worked well 4 drain lines but you will probably never see it again...EXPENSIVE!