Corrosion on copper pipe

[Kathy84]

We've just lifted the bathroom floor, and discovered what appears to be a 28mm gas pipe, with significant corrosion, apparently due to a water leak at some point in the past.

The pipe is not currently leaking, however I am concerned that the corrosion might pose a risk in the future. So my question is: is copper corrosion a surface level, cosmetic thing, or can it endanger the integrity of the pipe?

 

[just pumps]

It can corroded right through so regardless of whether it carries gas or water have it replaced.

 

[Kathy84]

Thanks! That was what I was afraid of. We've got a gas engineer coming tomorrow, to quote for rerunning the pipe.

 

[JohnD]

: is copper corrosion a surface level, cosmetic thing, or can it endanger the integrity of the pipe?

It can be either, but in most houses it will be trivial. You haven't shown us any photos so we'd only be guessing. Clean the pipes with a green nylon pan scourer and soapy water, polish off with a rag, and look to see if the surface has discernable pitting.

Usually it doesn't.

You'll recall that copper pipe often has water inside it.

Plumbers like to leave the pipes with a coating of corrosive flux round their soldered joints, which leads to green corrosion. They very seldom say that their slipshod work means that all the pipes will have to be replaced.

I prefer to spend a few extra seconds cleaning it off, but I'm a householder, not a professional

 

[just pumps]

Might be able to cut a section out and replace, may not be as bad as you think.

 

[JohnD]

show us a photo please.

if somebody tries to tell you that a bit of bath water leaking onto a copper pipe will eat a hole in it, I'd be really, really, really interested to see the evidence.

 

[Hot&Cold]

We've just lifted the bathroom floor, and discovered what appears to be a 28mm gas pipe, with significant corrosion,

Best to get it tested its your responsibility .

 

[Kathy84]

Thanks. As soon as I'm back at the house I'm going to try cleaning it, as suggested. Then I'll take a photo and upload it.

 

[Kathy84]

OK, I tried cleaning it with abrasive sponge, but that didn't do much, so used 240 grit sandpaper, which seemed to help. I went lightly, so as to not remove too much material.

There is a bit of staining left (like I said, didn't want to sand too hard), but no obvious pitting...

(edit to add: what looks in the photo like it might be pitting is smooth to the touch)

 

[Jajodu]

I wouldn't worry about that at all

 

[JohnD]

abrasive sponge,

do you mean a green nylon pan-scourer, or something else?

I don't think I've ever seen corrosion on a copper pipe that one wouldn't take off. Without scratching the copper.

 

[dilalio]

We've got a gas engineer coming tomorrow,

Then it'll be his recommendation you need to consider, nobody else's.

 

[Kathy84]

do you mean a green nylon pan-scourer, or something else?

I don't think I've ever seen corrosion on a copper pipe that one wouldn't take off. Without scratching the copper.

It was a white pan scourer, as that's what I had... I assumed (incorrectly perhaps) that it is be pretty much the same thing. If I get a chance to go get a green one before the engineer takes a look tomorrow, I'll have another go at it.

Thanks for the advice.

 

[DaveHerns]

Leave it alone and let the engineer see the full extent of the problem, not try to hide it from him.

 

[rsgaz]

I assumed (incorrectly perhaps) that it is be pretty much the same thing

The white ones are "non-abrasive", for non-stick/Teflon pans.
The green are the modern version of a 'proper' scourer, for stainless/cast iron pans.

BTW, The Statue of Liberty has been 'corroded copper green' since c1920 and she's not due to collapse any time soon! Ignore it.