My indoor copper water pipes have green spots all over them!?

Question

My indoor copper water pipes have green spots all over them! I noticed it over the years, but now it's much worse. What's this???

~Cindy! :O

Answer 1

I've seen copper piping with the corroded pinholes still last for years upon years.
They are little leaks that coroded up and stopped.
But the big leaks will come, one of these days.

But still plan a repipe even though you may have a lot of time. Start putting change away for it, because a complete residential repipe in my area is 1500 dollars starting out.

Answer 2

Copper pipes are connected by soldering them together.
The soldering process requires application of an acid flux to remove oxidation from the copper during the soldering process.
It is likely that whoever did the soldering left some acid residue on the surface of the copper. Over a period of time, the residue promotes corrosion. Copper turns green when it corrodes.
It isn't a problem, but if you want to eliminate the green, use an abrasive "Scotch Pad" and a mild soap and water solution. Rub the copper pipe with the pad dipped in the soap & water. It isn't a lot of work, but the copper pipe will be very bright when finished. The remaining pipe that you don't scrub will be dull.
Rince when finished and the green should not return.

Answer 3

I've always been told that copper was so much better than any other material for plumbing that there was almost no comparison. However, since I've been repairing plumbing in homes for the last 30 years or so and have had to remove hundreds of chunks of copper pipe from inside walls that have corroded, with the green patches you're talking about, until they've developed small leaks which then turn into big leaks, I won't plumb anything that's going to be inside or under or above anything else, with copper. I use either Pex, or CPVC or galvanized iron pipe wheneven it's going to be a hidden application. That way I can be sure that it's not going to leak in the future. I'd never put copper underground or in cement. I've had to dig way too many pipes up with a hammer and chisel to do that to anyone else.

Answer 4

For the best answers, search on this site https://shorturl.im/awAIs

Oxides of copper are all green. Any copper exposed to the environment will oxidize and eventually will turn greenish. The reason why SOME copper does NOT oxidize is because it is coated with a clear plastic or paint, which separates the base metal from the air and means no corrosion. The same applies to every metal. All metals form oxides on the surface. Some metals like iron and copper are obvious as you can see the oxide after a while. Others like gold, not so obvious. The oxide layer is either tightly bound and separates the base metal from the environment or porous which does not separate the metal from the environment. Gold is tightly bound and so thin you can see through it. Red rust is porous. Copper is sort of half way in between, forming a semi-porous layer which after a while gets thick enough to separate the metal from the environment and stop the corrosion from going any further, like applying several layers of paint when one layer or two is not enough to cover the existing color. ALL copper buried in the ground is coated to prevent corrosion. In your case, that coating was damaged in places, and everywhere it was damaged, copper oxide formed and turned the damaged spot green. Someone, probably not a professional as a professional would KNOW to be careful of the coating, was not very careful when installing the copper pipe, so it is possible you should worry. If you look closely, I'll bet you see actual damage to the copper under the oxide where it was dinged or scraped in some manner.

Answer 5

Green Water Pipes

Answer 6

Green spots on copper are the equivalent to rust on iron. This happens more often where solder paste has run onto areas of the pipe (as previous answer). One more caution, if there is an actual leak, you will see a small drop appear at a specific spot and then when it gets big enough it runs down the pipe. Sweating will be more area general. Leaks can happen particularly on ageing thin wall copper pipes. If so replace the pipe.

Answer 7

When the plumber installed the pipes he used acid past (commonly known as flux) to clean the ends of the pipe before sweating them together. The green is the residual paste that was never cleaned off the pipe. The acid is still etching the copper. The green spots are the result! Just get some detergent and water and sponge them down. It will dilute the acid and hopefully it hasn't etched a leek into the pipe.

Answer 8

Cindy,

The green stuff is caused by calcium buildup on the pipes. The pipes are fine!! This happens in just about every house containing humidity.

The pipes sweat and dry leaving corrosive calcium on the pipe. Calcium is abundantin hard water scenarios. (homes without water softeners tend to have very hard water.

Sometimes where you see the green you wil also see white powder kind of like a battery terminal on a car. It's nothing to be worried about. The pipes are not leaking and don't need to be replaced until they do.

A good dehumidifier can help prevent this problem also.

Answer 9

Not a panic situation if it has been going on for years.

If the green spots are along the pipes, don't worry, it's just oxidation. If they are at the joints, look to see if there is a crusty buildup. If so, there may be a small leak. If not, again, just oxidation. If it were on a copper roof or a copper garden ornament, it would be called a patina.

If the joints are leaking, call a reputable plumber and he may re-sweat them. Insofar as plastic is concerned, it's not legal all over. You need to check with the local building department.

Good luck

Answer 10

This condition is universal and nothing to worry about..Trust me. All copper pipes "sweat" from moisture in the air around them. This moisture condenses on the copper cold water supply pipes as the water evaporates, a greenish residue forms from minerals left behind on the copper surfaces after the water evaporates.This happens in every home no matter where you live........The more greenish build up just indicates higher humidity in the air..Nothing more..........Nothing to be concerned about.