I'm a little curious about a plumbing issue I thought of while still in the design phase of my green home.  What I was wondering about is if I use rammed earth (or even concrete) would the metal in the pipes embeded in the floors and walls react with the medium around them.  Like if I used copper pipes, would the copper corode or dissolve over time.  I would prefer not to use PVC or plastic or rubber pipes ...  What would be the best metal to use?  Also can I go pipeless?  Let's say while I'm laying the rammed earth floor can I use a curtain dowl to create "pipes" in the earth and then pull the rod out after it cures.  Would a constant flow of water (like in a radiant floor) erode these "pipes" over time as well?  I am just wondering about some of these things while I'm planning.  And I don't mind doing the work, in case you're wondering.

Along the same lines (but probably another topic), if I want to use steel in the support structure should I have it coated with something so that It doesn't corrode over the years of contact with rammed earth?

Thanks again guys ... and gals.

I am not a expert on rammed earth construction. But I have seen the effects that water has on dirt, and the two do not mix well. OK actually they do mix well, that's the problem. Eventually the water will erode any type of earth that it is in contact with, period. I would also hesitate to use any type of metal piping that is not heavily waterproofed, in earth contact.

Reconsider not using PVC, It will out last metal, copper just about all of them. There is a reason they don't use metal anymore.
I used pex in my house for the first time and am very impressed with it.

I thought PVC wasn't very "green" that's why I didn't want to use it ... What about clay pipes?

Expensive and troublesome. I understand wanting to build green but there are some things IMO that need to be modern such as anything that carries water.