Capping copper line under slab....

[Angelfire]

Hiya Folks,
In the throes of doing my addition, we had to cap a copper line that was run under the slab. It was a feed to an outside spicket and was capped down inside the stemwall. Well I'm getting ready to put wood floors in and lo and behold, it appears the capped line is leaking. I put visqueen over the area to check for moisture and sure enough, the concrete is getting darker. A hair dryer on the area confirmed there is moisture there. So the guy who did it is being a bit of a jerk about coming back to fix and quite frankly, if he couldn't do it right the first time, I'm not sure I want him messing with it again. I've sweated plenty of copper and the only times I've had leaks was due to poor prep or not getting the pipe completely dry so I don't have a problem giving this a go. My question is this. Is simply sweating a cap on the end the best way to go or is there another method to encapsulate the end so I definitely won't have leaks? I'd really hate to get wood down only to find in a year that I've still got a leak under there.
Cheers.

 

[pattenp]

I think sweating on a cap is the best you can do. I assume the line doesn't originate somewhere above the slab where it can be disconnected.

 

[Angelfire]

I don't believe so. If it does, it's buried in a wall somewhere and not obvious. I'm more inclined to think that they may have T'ed it somewhere under the slab.

 

[Red05GT]

Sharkbite fitting is the way to go. No need to worry about getting the moisture out of the
pipe to sweat a new cap on.

 

[Angelfire]

hmmm. I've heard nothing but bad about sharkbites. May have to research a bit more.

 

[JakeKohl]

Sharkbite fitting is the way to go. No need to worry about getting the moisture out of the
pipe to sweat a new cap on.

Until the o-ring dries up...I'm still a little surprised that these are considered permanent, long term, solutions. Although I have no evidence to the contrary, we have seen many new "latest and greatest" construction things lead to disaster...like the original PEX tubing system that would fail after 5 to 10 years....Those fittings make me nervous depending on a simple o-ring for longevity like that.

 

[mobiledynamics]

ANgelfire -If you are familiar with sweating, I would not hesitate on sweating a new cap.

I use sharkbits all the time as caps when doing ROUGH work...
Once the walls, rough ins are good, caps come off, etc...

Solder is KING

 

[Angelfire]

ANgelfire -If you are familiar with sweating, I would not hesitate on sweating a new cap.

I use sharkbits all the time as caps when doing ROUGH work...
Once the walls, rough ins are good, caps come off, etc...

Solder is KING

That's pretty much how I've been thinking. And I've heard the sharkbites do work well, for temporary situations. I just don't like the idea of using them then covering them up with concrete. I will go ahead and just solder. Just wasn't sure if there was some way of filling the pipe with epoxy or something just to give a little added security before soldering the cap on! Thanks much.

 

[BD1]

Do you have propress fittings in your area ? Get cap from supplier and borrow gun for 10 minutes.

http://www.zorotools.com/g/00063650...nce&utm_medium=referral&utm_campaign=shopping

http://www.bing.com/shopping/27913-...ool&lpf=0&lpq=propress+tool&FORM=EGCA&lppc=16

 

[domain]

Do not do shark bites please. They have to be accessible AFAIK. Sweat it back correctly and check it.

 

[Steves32]

None of this stuff you are talking about is approved under a slab.
Only joint allowed under a slab is a brazed joint. No soft solder.
We use 15% silver solder.

 

[djjsr]

The Sharkbite website says you can use their fittings underground and in areas that are inaccessible.

I would never do it. It may take 10 or 15 years to start leaking, but I want to see it when it does.

 

[djjsr]

Only joint allowed under a slab is a brazed joint. No soft solder.

Interesting. I just talked to a plumber about this and he said it's ok to use 'k' copper, solder and wrap.

Maybe the code varies in different areas?

 

[Norcal]

None of this stuff you are talking about is approved under a slab.
Only joint allowed under a slab is a brazed joint. No soft solder.
We use 15% silver solder.

Finally some good advice, sweating joints & Sharkbite fittings are not a good idea underslab....

 

[Tim The Tool Man]

Your best option is to sweat a cap on the copper. Do not use the shark bite fittings, despite what their advertising might tell you. It has a rubber o-ring that will eventually deteriorate and leak into and around the slab and you will have a big mess. shark bites are only temporary and only for exposed locations.

After you sweat a new cap on test it under pressure. If when you are sweating the joint you see a small plume of steam shooting out, stop. Tear it back apart because there is water in the line. You can cram white bread in there to soak up the water (but in a dead line you might end up giving a home to some nasty bacteria... )

Copper and concrete don't play well together. the alkalis in the concrete will eat through the copper eventually so you want to protect the pipe before you pour. Sweat a cap on it with regular solder, seal it in a PVC or plastic well pipe, then bury it in your concrete and you'll be fine.

 

[Riverjet502]

Another thought if you have problems getting all the water/moisture out of the line your trying to cap to get a good sweet joint. Take a brass compression union, sweet a ****** & cap on at the work bench one end, then install on copper pipe you want to cap off. Then forget about it.

 

[Angelfire]

Thanks folks for the replies. I broke out the concrete and found the capped line.....doesn't appear to be leaking although the soil around it is pretty wet. And there is clearly water in the concrete. It's been capped for 7 months so I figure a very, very small leak may still be there. Wrapped it in tissue and covered with plastic to see. I really hope this shows the cap is leaking otherwise I may have a pinhole or something else going on. A bit of a mystery as this is the only water source within 25' and the only place the concrete is showing dampness.

 

[1320stang]

I don't believe so. If it does, it's buried in a wall somewhere and not obvious. I'm more inclined to think that they may have T'ed it somewhere under the slab.

If it's done to code, there shouldn't be a tee anywhere, unless it's brazed and that's a "no other choice" solution. There shouldn't be any joints under the slab.

 

[Angelfire]

Yeah I agree. Unfortunately, during the addition, I have discovered a whole lot of inconsistencies and code misses. Hell, I don't even have rebar in my stemwall! My current inspector indicated that the house was built during a time when the inspectors office wasn't exactly stellar. So there's no telling what I've really got.