Renovating a small old two-story duplex to rent out, which has been a long process.
The apartment downstairs finally ready to rent, and the renter is raring to move in- in fact has already transfered electrical into their name.

Just as a last check, I thought I would double check all the fixtures in the unfinished apartment above. Ran the shower and tub at full blast and went downstairs into lower bathroom.
Drip... drip... drip.

I got into the ceiling over the shower downstairs, and I can see water dripping from two places- one strangely enough is the bottom seam of the vent stack, where the tub drain meets the vertical sewer pipe.
This is higher up than the downward bend of the drain (??). The only thing I can think of is a blockage further down the stack, but the tub appears to be draining fine, not even slow.
The other dripping is happening from somewhere where the pipes meet the tub high up, which I can't really see looking up through ceiling from downstairs below.

Anyone have any suggestions or seen this before? There's an old drain trap on the way to the vertical stack but the house was built in 1920... I've already been warned when these really old galvanized traps are opened they may never seal again.
Might have no choice but to chance it :/

 

A leak is never caused (directly) from a blockage. The plumbing system should be completely sealed, so I can practically guarantee that a blockage isn't your issue.

A common place for tubs to leak is at the strainer if it's not installed properly. It would likely cause a drip near the trap. It's possible for the water to be travelling down the outside of the pipe and dripping elsewhere too. A good test is to stopper the tub and fill it halfway. If it's dripping, it's definitely the tub drain/strainer. Once you release the stopper, if it leaks, then it's definitely in the piping itself (or where the tub drain connects to the trap.

The connection between the horizontal drain and stack is a less likely place for the leak to occur, though of course it's possible.

If the upstairs is unfinished, this might be a good chance to replace the galvanized with PVC. It's only a matter of time before the galvanized fails, and it's much easier to fix now if everything is open.

 

See above link. Some pictures would help in fixing specific problems.

Basically, you want to replace any pipes you can while you have the ceiling open.

This usually means at a minimum, cutting out sections of old pipe, replacing any cast iron tees, and running new drains from the new tees.
If you do it yourself, the cost is low.

 

OK here's the thing that's just absolutely bizarre. I ran the tub and shower yesterday maybe 5 minutes total and it all went down the drain. When it was running, I could see a trickle from the vent stack seam above the downward bend of the drain pipe and some dripping from high up connecting to the tub as I said, but that stopped after I turned off the water. Then looking from downstairs, I couldn't see any dripping from those areas.

However, the ceiling below these areas is still dripping! The water obviously went somewhere. I drilled a couple holes in the drywall to let the water drip, and put a bucket below them last night.
This morning the bucket was FULL. And the dripping continues. So at least a gallon of water collected up there, somewhere when I ran the tub and shower, and was slowly dripping overnight. Wth??!!
The only thing that I can think of that possibly makes sense is there is a blockage in the sewer stack, and the water ran down the drain and backed up in the pipes, going up the vent stack. As there is a crawlspace between the floors about 2 ft high, it will still be below the level of the tub so I guess that would be possible.
I'm about to risk opening the trap below the tub in about 20 min, and if that's right a bunch of water should dump out. Hoping of course the bolt isn't rusted and breaks off.

I'm trying to get pics, but my phone is tied up currently as soon as I can I will post.

 

OK I've got pics pics pics..... but no way to get them off my phone currently as I have no USB transfer cable here. Unless I can MMS them, if anybody is interested let me know.

 

I became suspicious last night as the dripping was still happening, and finally thought to try testing the main water line shut off and on to see if the dripping was affected. Sure enough, it stepped up when the main line was open, and slowed when it was shut off. So it had to be the supply side :/

I finally broke down and cut another large hole in the bathroom ceiling so I could see better..... and part (or perhaps all) of the mystery was spectacularly revealed.
Here it is, a heavily corroded 1/2" galvanized pipe tee. This looks like its been leaking for years, and what's more the previous owner seemed to be aware of it because he suspiciously lined the ceiling behind the drywall with plastic. I was the one who made it worse, by threading the pipe upstairs when I put a new stop valve on it a few days ago. I just happened to test the tub right after that, and of course had assumed it was due to the tub drain.

I've already got plumbing company estimates at $500 "and up" to swap this tee out, and I don't like the way that sounds to be sure.
First I'd like anyone's opinion about epoxy steel pipe tape wrap on this. It looks horrible, but is it as bad as it appears? And would starting to saw into it make things far worse.

If that doesn't work, the way I see it, I could attempt this myself, hacksaw it out and at least attempt to remove to the non-corroded joints with a lot of PB Blaster... and screw in new replacements. Its the hot water line which is shut off and I believe I'd take it alot slower and more careful than some guy I hired on the clock who makes more money the worse the problem gets. The tee up is just a straight pipe to one hot water sink tap.
Thoughts???

 

You are in luck. That's an elbow, not a tee and much easier to fix.
Remove all pipe back to the elbow, and the elbow.

- Start removal in the bathroom. Remove any valve and nipples coming out of the wall horizontally
- In the ceiling remove the vertical pipe going up to bathroom and the pipe and elbow.
- After elbow is removed, if the long pipe male threads are corroded away the fix will be harder. Let us know.

Install in reverse of taking apart, starting at the elbow with arrow.
Anytime you are working with pipe, use two pipe wrenches; 1 to hold the previous pipe from moving and one to tighten new fittings.

The only parts you need are Teflon tape, pipe dope and replacements for the parts you remove.




Edit:
Oops, I saw the Tee after posting (thought it was a nipple)... That's tricky. Can you see where the pipe that comes off of tee terminates? Or do you know what it serves?

 

That line goes off somewhere else in the house, I can't see.
But it has a short 4" pipe attachment that doesn't look too rusty.
The other attachments to the "rusted fork" look to be in pretty good shape too.
It all seems so doable..... I even have a quick-cut tool with a metal bit, and a galvanized pipe threader if I had to cut a piece off. The only problems I can see being not being able to unscrew or somehow not being able to screw in the replacement, getting the wrenches in there with good leverage.
In theory I could replace this middle part with say PEX with transitions or copper, but it seems like new galvanized with pipe dope might be simplest. I could replace the whole riser with a red pex tube if need be.

 

I'm thinking maybe PEX transitions like this guy did is the way to go. Screw the transitions on all loose ends, pop on the PEX with rings and clamp.
The reason being, I can't see how to screw everything back together due to the constraints of the fork. The PEX would be flexible enough to fit it into place and not involve screwing.
Its not pretty, but as long as it holds why not?


https://www.youtube.com/watch?v=K2Y6QrbiCJ0

 

That's the problem, you have to start at one end and replace everything.
I'm having difficulty with this and I apologize. Replacing the pipe up into vanity is easy.
As far as the tee, the only solution I see is to replace everything as it is now, with the exception of the short pipe that goes up at an angle.
That angled pipe will be replaced with 2 short nipples and a union.
Only problem is I don't know if unions are allowed in concealed locations.
Check a local plumbing supply store and they should know.
The union will allow you to connect all pipes normally, which is pretty easy, and still tie into the old pipes at that mid point.