Copper pipe in a concrete floor

[hellymedic]

and it all makes work for the working man to do...

[ElyDave]

you can buy a sort of u-shaped with a flange plastic section to mount flush at floor level, into a channel chased into the concrete, some friends of mine did this for their kitchen rebuild.

I had a plumber line a wall with a larger pipe as a conduit before running the supply to the gas fire, for exactly this reason.

[Canardly]

WB is it possible to cap off the section of pipe in the screed and to run a new length clipped to the wall? May be the most cost effective in the end.

[Wowbagger]

WB is it possible to cap off the section of pipe in the screed and to run a new length clipped to the wall? May be the most cost effective in the end.

I am intending to collar the loss adjuster with this precise suggestion on Monday.

[Quisling]

Thread hijack alert!

I'm in the same boat as Wow' was.  Domestic hot water pipe sprung a leak under the (new ) kitchen floor.  Fortunately not under any of the new kitchen cabinets.  Fortunately it was the hot water so we spotted it quickly (unexpected underfloor heating...) otherwise the cold would have been missed for ages.

I've managed to lift one floor tile and excavate down to the pipes and have found "the leak" (not ruling out others elsewhere yet).  The floor construction appears to be:
* DPM and blinding screed.
* pipes laid on top of this and wrapped in thin polythene
* top screed laid on and around pipes.

Unlike Wow's situation, there is no realistic hope of re-routing the pipes and surface mounting them.  This then begs the question as to how best to repair the 15mm copper pipe.  I'd rather avoid excavating more floor than necessary but may need to go wider to give working room.

Assuming I do a minimum chop out and repair, I'm stuck with the following facts
1. the two ends of the pipe are a fixed and immovable distance apart - so any repair needs to be capable of being fitted between two fixed points.
2. the pipes cannot be dried (since they're the lowest point on the system so there will always be drips) so soldering slip couplers in place is not an option.

How would you fix this? 
Is this the answer:  https://www.toolstation.com/shop/p68637?mkwid=s5P3L3jnK_dc&pcrid=142003768299&pkw=&pmt=&product=68637&gclid=EAIaIQobChMIu77IkunJ1QIVpJPtCh1x

or this?
http://www.screwfix.com/p/jg-speedfit-15rkp-slip-coupler-repair-kit-15mm-x-15mm/60242?kpid=60242&gclid=EAIaIQobChMIu77IkunJ1QIVpJPtCh1xQA09EAQYBCABEgIZ4PD_BwE&gclsrc=aw.ds&dclid=CIPxqp3pydUCFSOgUQod3UUCgA

or something else.

Either way, I'll be left with Joints Under The Floor which will spell doom for the future I'm sure.

[mrcharly-YHT]

Difficult to say without seeing it. I would be inclined to try slipping a straight Yorkshire fitting over the area and soldering in place. One cut at the hole. Very careful removal of flu afterwards.

[Ian H]

Why has it sprung a leak?  Is it sub-standard copper and thus likely to degrade generally?

[David Martin]

Why not take a yorkshire fitting and slice lengthways, then solder in place having used a bit of wire to twist tie the two halves back together around the pipe. Puncture repair stylee.

[mrcharly-YHT]

Why not take a yorkshire fitting and slice lengthways, then solder in place having used a bit of wire to twist tie the two halves back together around the pipe. Puncture repair stylee.

Definitely worth a try

[Fructify]

Why has it sprung a leak?  Is it sub-standard copper and thus likely to degrade generally?

If you're cutting out a section perhaps slice the cut out section in longitudinally and try and identify if the hole is from corrosion on the inside.  If that's the case after you've repaired it be prepared for it to leak in the next weakest place once you've repaired it.

[Quisling]

Thanks all so far.

As mentioned in my post, soldering options are unlikely to be successful.  The pipes are under the ground floor screed.  Total draining and isolation of the leaking pipe is unlikely to be successful since the upstream side feeds various legs leading to showers, baths, basins etc. Even if I open all the taps there will be ongoing drips downhill for a considerable while so it's safest to assume I'll never get the pipe adequately emptied and dry inside and out for soldering.

I think I'm going to initially try to cut out the split inch or two of pipe and use a brass compression pipe repair piece (as per my link in earlier post) because this is substantially less bulky than the push fit plastic option.  I think I can just about get the spanners in to nip it up.  In the meantime, I've bought a temporary clamp (this sort of thing http://www.screwfix.com/p/kibosh-emergency-pipe-repair-kit-15mm/59728?kpid=59728&gclid=EAIaIQobChMIn_zRuqfK1QIVbbXtCh00PA-cEAQYASABEgLQ9_D_BwE&gclsrc=aw.ds&dclid=CK_3msenytUCFUKo7QodJeILIw ) so I can do a bodge fix and check there aren't other major obvious leaks pouring water into the excavation.  If further leaks are evident then it's probably a case of ripping up 4m of floor and replacing the entire pipe lengths to be on the safe side.

Assuming only the one leak location then once I've cut out the pipe I'll check the general condition of the pipe walls and see what are the appropriate next steps.

If I was laying pipes I'd duct them or at least surround them in sand before screeding over the top.  I suspect a piece of aggregate in the uneven concrete has imposed a point load (split is in the top of the pipe) when we were doing building works / kitchen re-fit between November and April.  The builders cut out a wall and dropped a load of masonry onto the floor so that might have been enough to do some damage. This has possibly been exacerbated by additional thermal expansion resulting from switching to the immersion heater in the summer which has heated the water a bit warmer than normally provided by the boiler settings.  It's possible there has been a weep in the pipe for years, although the surface of the screed was dry before we re-tiled the floor.

Wish me luck.  Plumbing is my evil nemesis.

[mrcharly-YHT]

I recommend getting some Fernox ls-x to smear all over the olives and faces of the compression fitting.
https://tinyurl.com/ybdetl8v

It makes a huge difference when making up compression joints, stops weeping leaks.

[Little Jim]

I'll second Mr C re the Fernox.

I doubt that you would be able to get a push-fit coupling onto the pipe as it needs the ends of the pipe to be pushed into it (if you see what I mean) so that means that you can get it onto the first piece of pipe but then you need to be able to slide the second piece back to drop the joint down into the pipe run and then slide the second piece of pipe back into the push fit joint.  The slip coupler allows you to slide it right along one piece of pipe as it has no central register and then, once the pipe and coupler is dropped back into the pipe run, to slide it back across the joint.  That will undoubtedly repair the hole, but do take the opportunity for a quick check of the rest of the pipe that you can see.

[Quisling]

I'll second Mr C re the Fernox.

I doubt that you would be able to get a push-fit coupling onto the pipe as it needs the ends of the pipe to be pushed into it (if you see what I mean) so that means that you can get it onto the first piece of pipe but then you need to be able to slide the second piece back to drop the joint down into the pipe run and then slide the second piece of pipe back into the push fit joint.  The slip coupler allows you to slide it right along one piece of pipe as it has no central register and then, once the pipe and coupler is dropped back into the pipe run, to slide it back across the joint.  That will undoubtedly repair the hole, but do take the opportunity for a quick check of the rest of the pipe that you can see.

Thanks.  This seconds my own thinking.  I'll get some Fernox.  I've mostly had no problems with compression joints but have had the odd one that wont seal and have used the old PTFE tape trick, but that's not practical here so some sort of pipe jointing compound is useful belt-n-braces.

[Kim]

As mentioned in my post, soldering options are unlikely to be successful.  The pipes are under the ground floor screed.  Total draining and isolation of the leaking pipe is unlikely to be successful since the upstream side feeds various legs leading to showers, baths, basins etc. Even if I open all the taps there will be ongoing drips downhill for a considerable while so it's safest to assume I'll never get the pipe adequately emptied and dry inside and out for soldering.

Does this matter for David Martin's suggestion of a fitting cut lengthwise wrapped round the outside?  Presumably it's not leaking that badly...

Also, isn't the textbook solution to this to stick a little bit of bread up the pipe to catch the drips?  You then introduce sticklebacks at a convenient point in the system to nibble the bread, I suppose.  Sounds like a terrible idea to me.  Freezing the pipe would seem more likely to work.

[Quisling]

I'm a fairly competent solderer, at least using Yorkshire fittings - I've not done end feed much, but it necessitates getting the pipe surface really clean - at least of the chunky dirt - before fluxing it ready for soldering.  I think the underside of the pipe will be hard to do, given the reasonably significant external grot.  On balance, whilst I prefer soldering, I think the compression fitting with jointing compound for good measure seems the most reliable option.

It would help if I hadn't also hit the adjacent cold pipe when drilling into the concrete   Whilst not leaking, yet, I know I should fix that one too while I've got the floor up to be on the safe side

[David Martin]

If you have room for a compression fitting then you have much more room than needed for soldering. A decent bit of emery will get the pipe sufficiently clean, and with some flux shouldn't be a problem. End feed are not so much harder than Yorkshire.

[Aunt Maud]

There must be some way of disconnecting those pipes and re-routing them elsewhere. Failing that just dig them up and putting them in a bit of ducting, so you can get them out next time you drill a hole in them.

If you want to try and bodge a repair....

https://www.toolstation.com/shop/p68637?mkwid=s5P3L3jnK_dc&pcrid=142003768299&pkw=&pmt=&product=68637&gclid=EAIaIQobChMI2PSeqITM1QIVZrvtCh1u

http://www.screwfix.com/p/solder-ring-slip-coupler-15mm-x-15mm/56343

And don't concrete around the repair, but slip a bit of foam insulation over it and stick the tile down loosely so you can get at it again.

[Brucey]

you can clean up the far side of a manky pipe (eg using a strip of emery cloth) very well.  If you are in any doubt, use a more aggressive "active" flux. End feed fittings work very easily indeed BTW,  provided you use the right flux etc .

I find that with Yorkshire fittings they are often a bit short on solder so it is a good idea to add more anyway. If you are going to do that you may as well use end feed ones to start with....

If you are in any doubt about the effectiveness of an active flux, just heat a dirty copper tube with a little of the flux applied; the effect is almost miraculous, as grotty old pipe is magically transformed into shiny fresh copper....

cheers