I've had copper half buried in regularly wet cement for decades. I chipped a bit away to find no corrosion. Lots of houses have pipes in floor concrete, but resulting leaks are very rare.
(Reply to anonymous contributor) That's a bit like saying my Auntie Elsie smoked 60 a day all her life and didn't get lung cancer, heart disease etc and therefore it's a myth that smoking is harmful. FWIW I have several times seen copper pipes buried in concrete that are corroding. It's generally accepted that this may happen and that it is bad practice to install pipework this way (illegal in the case of gas), so I've changed the text to indicate this.
--John Stumbles 11:04, 24 December 2006 (GMT)
Millions of houses have copper in concrete, but corrosion leaks are rare, smoking deaths are common. Not comparable.
The prime reason for denso et al is thermal expansion rather than corrosion. Copper carrying hot water in concrete can pull soldered joints apart or break itself as it expands and the conrete doesn't. There was a thread debating this in ukdiy recentishly.
(Reply to anonymous contributor)
Do you have a reference to the thread (at google groups)?
With regards to gas pipework; movement - due to thermal or other causes - is referred to by BS6891:
8.8.3 Pipes buried in concrete ground floors shall be protected against failure caused by movement
But the Standard also talk about corrosion:
... Reference should also be made to 9.2.1 for the application of adequate corrosion protection.
Where 9.2.1 is:
9.2 Buried pipework 9.2.1 Internal environment 126.96.36.199 Pipework that is buried in a solid floor or wall shall be factory sheathed, or protected on site by wrapping or with suitable bituminous paint protection. ... COMMENTARY AND RECOMMENDATIONS ON 188.8.131.52 Protective measures are applied as a precaution against electrolytic and/or chemical corrosion.
BS5444(1990) (on Central Heating) recommends:
Where it is necessary to run short lengths of circulation pipework in concrete floors or in walls they should: ... be adequately protected from damage and corrosion
I've certainly observed corrosion to buried pipework in practice. I'm sure thermal and other stresses on pipework buried directly in concrete, especially carrying hot water, may also cause problems. However the practical implications are surely the same: buried pipework requires adequate protection against these problems (as well as from heat loss in pipes carrying hot water, natch).
Risk factor magnitude
I guess its all a question of the magnitude of the risk factor. If millions of houses have copper direct in concrete, yet gas leaks from this are a rarity, then we could conclude that corrosion is a minor risk, one far below the level of the many other risks in houses.
This doesnt make a difference with new installs, but it does matter to whether people with existing copper in conrete would be well advised to dig it up or leave it alone and concentrate on the bigger risk factors in homes.
I googled but didnt find the thread I had in mind. NT 05:34, 2 January 2007 (GMT)
I think I see what you're getting at. From the POV of new installs it's a no-brainer: protect the pipe, for whatever reasons; but as you say, what if you find you have existing copper in concrete? If it's gas then although the probability of failure may be low the consequence of failure may be very high so it must be taken seriously. In the Gas Industry's classification of Unsafe Situations it would be Not to Current Standards if not showing any visible sign of corrosion (e.g where the pipe meets the concrete) or At Risk if it is. (Of course if it's leaking - which I have come across - it's Immediately Dangerous.)
For water pipes I'd say keep an eye on them and replace if possible e.g. if there's work going on in that area which makes it convenient, or before laying your £75/sq.m. hand-fired porcelain tiles over the top!
--John Stumbles 14:38, 2 January 2007 (GMT)
All in one?
Should all plumbing topics be imported into one huge plumbing article? I can see it being a very hard to digest article if its like that, and also harder to write for.
Re copper in concrete, I think there is significantly more to be said, and I think a fair sized piece on it within a general plumbing intro/basics article would be out of place, which is why I began it as a separate piece. Personally I think it needs to be a separate piece. Your thoughts would be appreciated. NT 19:08, 29 January 2007 (GMT)
As it stood someone reading the plumbing article wouldn't know the Copper Pipe in Concrete article was there. I could have put a link to it but as the Copper Pipe in Concrete article itself was little more than a link to the CDA article, and there was already a discussion of copper in concrete in plumbing, it seemed to make more sense to amend the text and incorporate the link to the CDA page directly into the main article.
If the section on copper in concrete becomes big enough that it would be out of place in the main article then it would seem reasonable to say something like "there are issue concerning copper in concrete" in the main article and link it to a separate article giving the full discussion of the issues. However at the moment the copper in concrete bit is only 150 or so words so it doesn't seem (to me) to be overweight for inclusion in the main article. What do you think?
--John Stumbles 10:30, 30 January 2007 (GMT)
I understand what youre saying, sounds sensible. But I plan it to be bigger in its own right, as and when i get the occcasional tuit.
I guess it comes down to writing, plumbing is primarily your article, and you know where youre heading with it, and vice versa, so if we keep rewriting each others article I can see it just adding a bunch of time and hassle to the process. I guess thats one reason I started it separately too.
- Seems to me that's also the strength of wiki-ing. E.g. until you made changes to the thermal stores article I'd not really even tried to see how other people saw it so didn't appreciate how it could be better --John Stumbles 20:01, 30 January 2007 (GMT)
I also feel like writing something about producing articles, but dont know where that would belong. NT 19:14, 30 January 2007 (GMT)
There's a bit about it on the main page and there's the example article. I've been a bit leery about putting more than howto/formatting stuff in as it gets personal and people have different styles. We've already seen that in the different way you and I tend to approach it (of course I'm right and you're wrong! ;-). Actually since it's pretty much just you and me doing this wiki at the moment there doesn't seem much point in it right now! Maybe when/if we get more contributors we might hammer out some sort of style guides (as wikipedia has). But seems to me that first we've got to get a fair amount of useful info into it and have people start referring to it on the group and finding it with google, then when people find it's useful they're join in contributing. I hope :-)
--John Stumbles 20:01, 30 January 2007 (GMT)
Thinking about it some more, I'm not sure we even need a uniform style. Perhaps we will one day if more significant issues crop up.
Re personal styles, we could have an article where each contributor that wants to explains some of the ideas they personally use when writing articles, without there being any attempt to come to a single agreed style or set of guidelines. Then its just some ideas for writers to look at, and ignore, or choose the best from.
Re the copper in concrete one, I think the best thing is that its fine as is for now, since the seprate article contained little, but if I expand it at some point I'll do that as a separate article, and leave you do whatever you think best within the plumbing one.
This wiki has covered a lot of ground so far, and is already good for a fair number of references in ng replies, not that I've been there a lot lately. NT 22:07, 30 January 2007 (GMT)
What are these field drain pipes made of? I thught clay pipes were red. NT 23:41, 26 August 2012 (BST)