I have been struggling with this problem for some time, since 2013. A slow drip behind the tiled bathtub wall caused by pin holes developed in the copper kitchen drain pipe.

There is no easy access to the pipe. I have cut an opening so I can touch the bottom of the pipe with my one arm fully stretched while wedged inside the kitchen sink cabinet. I can "see" the problem via endoscope from my phone, and I have patched the holes with plumber's epoxy putty and that fixed it for a few years then it came back.

The good news is the drip is really slow, although it has gotten worse recently.

The permanent solution is to replace the copper kitchen drain from the sink all the way to the stack 8' away. To do that I need to cut open the back of the kitchen cabinet, and cut open the bathroom wall where the stack is which means removing a toilet, cutting that wall, cut and slide out the copper pipe section by section, and slide in new copper pipe and solder section by section etc, closed up the wall and cabinet and refinish everything. This will take me 3-5 days. During this time the kitchen drain can't be used, the toilet can't be used, so basically the place will be inhabitable.

The tenant has been there since 2013, and I have had several discussions with her to vacate the property for 5 days to let me take on this project. I offered to pay for hotels for 5 days, yet she is reluctant because she has 2 cats. Well I can't have 2 cats present while this is going on, where power tools, nails, screws, razor blades, solder, flux, blow torch etc...all kinds of stuff laying around where I have to worry about pets stepping on or swallowing, not to mention every time I open the door I worry about the cats slipping out. I offered to pay for her to kernel the cats, she doesn't want that either.

So finally I have a potential window on Easter this year, she will fly to visit her mom for 4 days, and she will have the cats staying at a friend's. So I am going to replace the pipe in late April - hopefully.

In the mean time I still have to find a temp solution. So far I have been putting a bucket under the drip, and visit the property every month to check. Last two months the bucket was filled to the brim, which means the leak is getting worse (as expected).

I have a thread which discussed the leak in details with pictures here. So I am not going to repeat everything here again.

[www.plbg.com]

What I am considering is to put together some ugly contraption to intercept the leak until I can replace the pipe end of April. So I would like to get your opinion if this is a viable short term fix or am I out of my mind to think of doing this hack

So this is the rectangular hole on the side of the kitchen sink cabinet. It allows me to see the bath tub and the common wall cavity (the other side of this wall is the bathroom and kitchen of the neighbor unit).



Here you can see the leak coming from the kitchen drain pipe above.



Here you can see the underside of the kitchen drain pipe, where I have previously applied epoxy putty which solved the problem for a while. You can also see how congested the pipes are. I took this picture with an endoscope with my hand stretched into the hole pointing the endoscope up.



In the mean time, I am catching the drip with a bucket placed on the sole plate. This bucket is half filled sometimes and filled up and spilling sometimes, I guess depends on whether my tenant uses the dishwasher or not.



I am thinking of a way to have something beside the bucket to catch the drip and divert it somewhere. What if I take apart the bath tub's overflow pipes, and replace the middle tail piece with a 1.5" tubular baffle tee?



Then I can connect a p-trap outlet pipe and turn the elbow up. Connect a short piece of pipe and put a larger funnel into that pipe. I just need to have the right length and rotate the baffle tee so the funnel is right underneath the drip. Something like this.



I think this will keep the situation under control till I replace the piping in April. Stopping the drip will stop things from getting worse, the moisture will not attract mold, roaches, termites etc...

Thoughts? I know this is not best practice and I try to do the right thing but I can't think of anything else. It seems easy enough so worth trying?

I know by doing this I am allowing air from the common wall cavity into the bathroom through the overflow pipe.



Edited 4 times.

Sum, do yourself a favor and save a lot of heart aches......Re-pipe above ground only.

"Re-pipe above ground only."

srloren, do you mind elaborate what you mean by "above ground only"? The pipes are above ground. The re-pipe is not feasible till Easter weekend 2019. I am looking for an interim measure for the next 60 days.

Sum, that works for me. It's like a condensate drain into a sink tailpiece.

Sum I love the hack. To keep that funnel in-place, check out a polyurethane glue like “pl premium” at HD in the caulk section. That stuff sticks to everything.

sum, you could also use a dishwasher tailpiece with a piece of hose and the funnel.

either one will work

Packy yes I was thinking about that too. I might get both and figure out on site which one works best. I do need to put some sort of wood blocking under it to support the funnel/hose/pipe thing.

One question is, should I put a p-trap into this thing? In other words, the drip runs down the funnel right into the baffle tee or this dishwasher connection, or should it go through it's own p-trap so the air in the wall cavity will not travel to the bathroom through the overflow hole. Doesn't seem like it's necessary but I can put in a p-trap just as easy.

well, if that is a concern then get a trap primer tailpiece. the short piece of hose will form it's own trap.
make sure to get the funnel high enough so no tub water will back out of it.

there is always more than one way to skin a cat.

Thanks Packy on the reminder about the funnel height.

I know it has to be higher then the height of the branch where I hook up this contraption.

But does it need to be higher then the overflow hole height? The only scenario I can think of is the tub drain being totally blocked, water fills the tub up to the overflow hole, runs into it and have no where else to go so it spills out of the funnel and floods the wall cavity. But this is unlikely since we are talking about 60 days and my tenant takes showers not baths.