Topic: Slab Leak! (Drywall repair)

[fmctm1sw]

Gentlemen, thanks for the help and encouragement so far.  There's no better feeling than solving your own problems. 

[fmctm1sw]

Next was finding the other end of the source pipe in the wall.  This was on of my top concerns with the job.  I drilled a small hole in my wall about where the pipe should be based on the trajectory of the pipe under the slab.  I then fished a clothes hanger into it and turned it around.  Hmm, funny sound.  Drilled another hole closer to where the noise was.  I marked it with an arrow.  Found something!  I cut out a small piece of drywall and there they are.  I know it's the hot side because there are two red flags at the bottom of the pipes.  One heads up and over to the sink and then the clothes washer no doubt.  Now I just have to figure out which of the two pipes coming up is the lead to the water tank.

Edit:  Oh $#%^!    Pipe from tank is 3/4".  These pipes are 1/2".  Not them...

[fmctm1sw]

Well, the 3/4" pipe showed up.  Just wishing it was in the first place I looked though.  The Mrs was not happy with me poking holes in the walls.  Drywall repair was one of those "unintended consequences" I didn't pay much mind to.  I hope repair is easy.  I cut the wall right behind the second sink in the MBR and found it butt up against a stud.  I originally assumed it passed all the way to the washing machine.  Hmm, so what behind the washing machine?  Yep, the 3/4" pipe, and of course a cold run is right on top of it.  On the good side, it is the closest run to the water heater.  It reduces to 1/2" and splits to the hot side of the washer and two other runs.  I assume one run is under the slab to where the pipes for the sink came out of the slab are and the other would be to the second bathroom.  That would make the other run off the MBR sinks go to the kitchen sink.  That's the only thing left because the dishwasher looks split right behind the wall behind the sink.  Now it's a matter of determining the best way to go with fittings behind the washing machine.

[BeSeeingYou]

When you lay out your new system don't oversize the pipes.  You can put three fixtures on a half inch line.  Maybe more important on the hot side as keeping the pipe size down will get the hot water faster to the fixture.  On hot runs I downsize to half inch as soon as I can so less cold water has to be cleared out of the pipe for the hot water to get to the fixture.  A 3/4 pipe will carry twice the amount as a 1/2 and that will carry twice that of 3/8.  By the time the water hits the fixture it is down to 3/8-1/4 diameter due to the connecting hose or the fixture itself.

What is all over the pipe?  Some type of mineral build up?

[fmctm1sw]

What is all over the pipe?  Some type of mineral build up?

It's pretty solid on the pipes.  It may be that texture stuff that's sprayed on my drywall.  Other than that, not real sure.  I devised a plan for drywall repair.  The plan is to back the cutouts with furring strip, then screw the cutout to it.  Next will be to use that drywall paste on it but I'm good for now.

[BeSeeingYou]

That's how I do it.  Bigger holes will need more support but that's fine for the smaller ones.

[fmctm1sw]

I'm now in the pipe cutting and sweating phase.  When I discovered a 3/4" pipe coming up behind the clothes washer, I made the assumption it was the other end of the 3/4" run from my water heater.  So, I cut the 3/4" pipe off behind the clothes washer and blew in to the open end in my MBR closet.  It came out the other side of my cut    Not what I was hoping for.  I went back to the the small closet where I first found the two pipes coming out of the slab.  I cut the one closest to the water heater.  Yep, I was right the first time.  After a whole day of blowing into pipes and sweating parts back together I determined the 3/4" hot run splits into two 1/2" runs under the slab.  One of those runs comes up in the small closet and the other comes up behind the clothes washer.  WTF?     Now I know where everything is at.  I mended the run to the MBR sinks and kitchen sink.  I'll have to tap into it at some point.  I'll also make a run to behind the clothes washer.  That area feeds the clothes washer and 2nd bathroom.  I may need to redo the runs behind the clothes washer, I had a hard time sweating it back together where it was.  It would have been way easier to start from scratch but there's less than a foot of pipe coming out of the slab and I'm desperately trying to save my baseboards.  I also cut an access out in my garage above the water heater.  I guess that pipe is acting as a slam arrester.  I plan on going up into the attic there and maintaining a length of pipe like that after I tee off a run.

On another note, the run to the MBR sinks ends about 6 or 8 feet from the runs behind the washer.  There must be some good reason the 3/4" pipe was split and run to each of these locations right?  If I didn't know better (and I don't), I would think I could just cut an access in the stud between these runs and connect the all the hot water runs together.  Then I'd only need one run of pipe to tap into the hot water "circuit."  Pressure issues?

[fmctm1sw]

Well, it appears I really had no idea what pipe was what.  I've been at it pretty much all week.  Today I got everything sweated together and "hit the switch."  Water was blasting out of the original problem source hose in the MBR closet.  After a few choice words, I went back to the wall behind the washing machine and capped the run to that branch.  I did find one leak from a bad joint right above my water heater but that was before I noticed the MBR hose.  I wasn't even watching it at first since I was sure I bypassed it.  It would appear that 3/4" run behind the washing machine was the source.  So tomorrow I'll cut that and reconnect the run and see what happens.  For now I have the MBR sinks and kitchen sink back up.  The remaining branch behind the washing machine must consist of a run the the second bathroom and lead to where the original source to the MBR and kitchen sinks were.  UNLESS somehow those are individual runs, one for the shower and sink each.  Doubtful but nothing would surprise me at this point...

[faux fiddy]

Arrrggghh!

I've dealt with stuff I thought was a challenge but nothing like you got yerself in to.

I did deal with a ice maher pipe that came outside the sill plate where there should havebeen 2x6.   I had to coax the pipe  back behing the sheetrock, right at the slab very gently. Whittled away a little on the backside of the sheetrock, and everything I could to get a couple mm.

[Bob Wessner]

fmc, you're very patient. By this time I might have considered torching my house.

[fmctm1sw]

Thanks for your comments guys.  There were definitely times I wanted to call it quits but I like my tax return in my savings account vice someone else's pocket.  Mark the date and time, everything is back up and no leaks at this point.  I'm going to leave all the walls open another day, then start repairing the drywall.  Total bill at this point is between $300 and $350.  Some stuff I already had; torch, etc..  All copper and solder, no CPVC, PEX, etc.  I had a guy at Home Depot try to sell me on those sharkbite connectors but I already bought all copper fittings.  Not sure I trust them anyway.  Discussion of those in plumbing forums is about as volatile as oil and pod threads here.  And so is 1/2" vs 3/4" piping.  I'll post some more photos later.  It took me a very long time though, had I not been so tentative about digging into drywall, it probably would have went faster.  The fact that I was able to rig up one shower and the dishwasher really took a lot of the pressure off.

[fmctm1sw]

Here's a few photos of the work.  A lot of my sweats are nice, others...  well... they don't leak.  Not any worse than the sweats already in place on the piping.  I found it much more effective to do your sweats "on the bench" vice while in place.  Sometimes it's just unavoidable though to do it in place.  The 3/4" run came up from the slab behind the washer and fed the second bathroom, the clothes washer, and a run over to our small closet between the kitchen and utility room.  In the closet, there was a run to the MBR sinks and kitchen sink.  I made two drops from the attic, one behind the washer and one inside the utility room between the MBR sinks. 

[fmctm1sw]

Here's the start of drywall repair.  I'm going to leave most of it open for at least a day but I felt safe working the areas I worked on.  Not much to the drywall repair paste.  If you've done any bondo work, it will come natural.

[BeSeeingYou]

I would only use the Sharkbites in an accessible location and if it was too tight for soldering or PEX crimping.
Sometimes it's good to tackle this type of thing to give you confidence for the next thing that happens.

[Bob Wessner]

This might be a bit late in your project to suggest, but if you think you might ever have to go back into these areas in the future, rather than a permanent drywall repair, consider installing some access panels. You can find them at Lowe's, etc. in various sizes. When I finished our basement, there's a bump out housing some plumbing, including a clean out for a waste line. Below is a pic. Just a suggestion...

[Spanner 1]

Plumbers don't like Sharkbites 'cos it does them out of work... any Joe Soap can now run water lines with no soldering skills using Sb's.... they have been in use outside of the U.S. for years before their intro here and are well proven.... just my 2c. O.P.... I'm glad you solved the problem and admire your soldering job!
I couldn't do that for sure ....