Re-routing copper pipe in walls?

[jjl]

Hi, remodelling a downstairs cloakroom and discovered that the old installation had the water pipe to the toilet through a copper pipe chased directly into the wall (not encased in anything like plastic piping). It's not leaking and the pipe doesn't seem to be corroded, but thinking it might be wiser to take the opportunity to pull out the old pipework and route a new copper pipe through a plastic pipe so it's done properly. Or would that be overkill?

 

[Ben-gee]

Just wrap it in gaffer tape.

 

[Last Plumber]

If it isn't corroded, cover it in tape and re-plaster it in. No point doing pointless work. The copper is a better job than plastic (booooo) in my opinion! Just my opinion of course, doesn't mean I'm right.

 

[jjl]

If it isn't corroded, cover it in tape and re-plaster it in. No point doing pointless work. The copper is a better job than plastic (booooo) in my opinion! Just my opinion of course, doesn't mean I'm right.

Thanks - I meant putting a copper pipe in a plastic pipe (or sleeve? not sure what the technical term is). So just regular gaffer tape would do?

 

[Last Plumber]

Thanks - I meant putting a copper pipe in a plastic pipe (or sleeve? not sure what the technical term is). So just regular gaffer tape would do?

Yes you need to protect it against the plaster or cement it may come into contact with to avoid corrosion.

If you want to go to the trouble of sleeving it, then do it. It isn't wrong, it just isn't normally necessary.

 

[jjl]

Yes you need to protect it against the plaster or cement it may come into contact with to avoid corrosion.

If you want to go to the trouble of sleeving it, then do it. It isn't wrong, it just isn't normally necessary.

The issue is that it is already embedded in plaster/cement, so I would need to remove that to access the pipe, which would probably damage the pipe anyway. It might be easier just to rip it out and put in a new one. Alternatively, I could just put in a new pipe and leave the existing one in place (disconnected) it would save me the trouble of getting it out of the wall. Are there any rules for routing copper piping in walls? The existing pipe runs along the bottom of the floor and I could either put another pipe just above it, or higher up on the wall (which would be easier to access but might be an issue if someone later decided to drill a hole in the wall to put in a fixture).

 

[Ric2013]

Can I just point out that my house has a GAS pipe embedded in a wall? Whenever I've had a gas safety inspection the attitude has been that it's not to current standards but, as it isn't leaking... and it's been there at least 35 years. Realistically, while it's entirely possible your pipe will start leaking tomorrow, it's equally likely to continue to serve its purpose for another 50 years. If the wall is dry, I doubt any chemical reaction with the pipe will be a quick one, and if it's old imperial pipe then it's likely to be thicker than modern pipe anyway, so will last a while...

If, however, you like the idea of the pipe being replaced, then there aren't any particular rules about where pipe runs should be. Just don't bury any compression joints. Don't bother trying to remove the existing pipe from the wall in order to sleeve it. Either use it as it is and bypass it should it ever start to leak, or bypass it now and leave the redundant pipe disconnected in the wall.

One rule you should be aware of is that dead legs (dead ends of pipe that don't have water running through them but that are still under pressure) teed off a pipe must be removed to within a pipe's diameter of where they tee off, or, ideally, be removed altogether. This is to prevent stagnation of water and breeding of bacteria. So if you want to bypass the old pipe, you need to make sure you entirely disconnect the redundant length.

 

[Last Plumber]

The issue is that it is already embedded in plaster/cement, so I would need to remove that to access the pipe, which would probably damage the pipe anyway. It might be easier just to rip it out and put in a new one. Alternatively, I could just put in a new pipe and leave the existing one in place (disconnected) it would save me the trouble of getting it out of the wall. Are there any rules for routing copper piping in walls? The existing pipe runs along the bottom of the floor and I could either put another pipe just above it, or higher up on the wall (which would be easier to access but might be an issue if someone later decided to drill a hole in the wall to put in a fixture).

I agree with Ric so there's not much else to say. The protection for corrosion prevention is when the thing is covered with wet plaster or cement and also to prevent any reaction with condensation. As he said, the old pipe will be thicker walled and it hasn't leaked yet. It will probably be fine but due to the doubts you have, replace it, then it is done with.