Piping under concrete

[Rusti]

Hi,
yesterday whilst fitting a toilet to a concrete floor I drilled through a water pipe buried in the concrete.
It had been a long day and despite turning off the stop tap there was still a drip flow so I got a plumber out to fix it.
What surprised me was that he didn't use copper but plastic pipe with one brass compression joint onto the copper and a push-fit elbow to turn the pipe vertical where it will come up from the ground. He reckoned this would be better than copper as it wouldn't corrode.
Would anyone back this up for my peace of mind please?
Thanks

 

[studips]

what like speedfit or hep2O?
copper buried in concrete corrodes if not protected, there is nothing wrong with plastic, it's cheaper for the pipe, the fittings are similar cost to brass compression joints - whole houses are done with plastic, copper just does a smarter job.

 

[Rusti]

Yes, it is a speedfit joint and hep20 pipe.
It's just that someone told me copper lasts indefinitely (as long as its protected) whereas plastic will start leaking after 10 years or so. Do you disagree with this?
I'm going to fit central heating in a house soon and was going to use copper but maybe I should consider plastic if it's cheaper?
Thanks

 

[Norcon]

The sealing O rings can give trouble with time. Nothing wrong with modern plastic pipe.
Its the only solution that can give you a joint free installation in domestic installations where pipes are buried.
mlcp is a good option also if you're doing a large enough project.

 

[looneyfitter]

i have done numerous whole housing developments in hep/polyplumb over the last 5 years or so. Not once have i had a call back to a joint leaking.

 

[kevplumb]

bit iffty about burying a conex tho

 

[looneyfitter]

bit iffty about burying a conex tho

hadnt thought about that.... mechanical joints should always be accessable

 

[Agile]

The problem with buried copper in concrete is where its not protected/insulated and able to expand.

Even so a continuous length of plastic is safer except that an elbow is usually needed to come up to rads. Those usually come up in copper to make it look like a proper job!

Tony

 

[kevplumb]

The problem with buried copper in concrete is where its not protected/insulated and able to expand.

the problem is corrosion

 

[Agile]

ALL the leaks in concrete that I have ever attended have been leaking joints as a result of stress because the copper was unable to expand.

Tony

 

[namsag]

Agile , and you know that because ???
The general opinion of leaks on joints is because the flux has not been properly cleaned off and/or the joint is not wrapped and protected and corrosion occurs with the concrete and the joint

 

[Agile]

Corrosion is obvious as metal is lost and it can occur along the pipe resulting in holes.

Normally moisture is required for corrosion to take place.

I agree that corrosion can occur when unprotected pipes are burried in concrete.

But I have never yet attended a concrete burried corroded pipe ( water or gas ).

Tony