2nd Floor Bathtub Leak in Basement

Hi all,

I noticed a fast drip coming from the ceiling of my basement (not finished). I searched google and tried some basic troubleshooting but wanted to post my issue here in hopes of your support.

I was able to identify that the leak is coming somewhere from the hot water supply line as it shoots up to my second floor bathroom.

• I ruled out the bathtub drain and replaced that today.
• I also cleaned around tub and placed new caulk around the tub area

I'm unable to see the pvc pipe up to the bathroom as it's hidden behind drywall but what I can say is that the pipe only leaks when the tub faucet or shower head is running. There is no water damage anywhere that I can see as I checked drywall areas for softness. So it appears that it's a drip that runs straight down the pipe line to the basement.

For now, I've shut the water off to that bathroom until I can figure this out. My best guess is that it has to be a fixture of some sort. I'm no plumber but my educated guess is that when the water supply is active (faucet off), I assume I would see some sort of leak if there's a pipe crack. Again, if the water supply is active (faucet on), then I see the leak.

My next step is take apart the single level faucet from the tub. Is that correct? Is there anything else I should try before I need to call out a plumber? Obviously, I'm trying to save money and hoping not to tear up my walls to find the issue.

Any help is appreciated!

I am not an expert, but it seems to me that your leak is somewhere in the drain line. If a supply pipe had a leak, it would leak ALL of the time, not just when water is running.

Is there a "trouble door" or access panel at the water end of the tub? If so, open it, and reach under the tub and feel for wetness on the drain, or the drain shoe, or the trap.

jeffmattero76 said:

I am not an expert, but it seems to me that your leak is somewhere in the drain line. If a supply pipe had a leak, it would leak ALL of the time, not just when water is running.

Is there a "trouble door" or access panel at the water end of the tub? If so, open it, and reach under the tub and feel for wetness on the drain, or the drain shoe, or the trap.

Click to expand...

That's what I thought too, however, earlier today I did shut off the water supply and filled tub from another water source then drained without issue. I also replaced the drain fixture too just to be safe. Unfortunately, there is no "trouble door" which really surprised me but did knock around for soft spots but all seems well there. I'm stumped.

How about the pipe leading from the tub spout to the shower head. To test if that is where the leak is, just allow water to come out of the tub spout and see if it leaks.

What is the "drain fixture" you are referring to?

By process of elimination here are my thoughts
1 - if it is not leaking all of the time, the supply pipes are NOT the source of the leak.
2- if filling the tub using water from another source, and then draining the tub did not cause a leak, the the drain pipes are NOT the source of the leak

To me, that means that the source of the leak must be in the pipe that leads to the shower head. Test that and get back to us.

dvitale71 said:

That's what I thought too, however, earlier today I did shut off the water supply and filled tub from another water source then drained without issue. I also replaced the drain fixture too just to be safe. Unfortunately, there is no "trouble door" which really surprised me but did knock around for soft spots but all seems well there. I'm stumped.

Click to expand...

is the water from the spout on the tub, coming in contact with the trip lever

I would take the shower arm off and Teflon tape it and some pipe dope and put it back on. If it still leaks you
are probably going to have to open the wall behind the faucet and see whats leaking.

also check mixing valve...take trim plate off and look while running water to shower then tub. sometimes diverter will leak or packing on stem.

i would take mike fiores advice if there is a diverter that pushes from left to right or it pushes in that may be the sourceif the tub spout is off the wall a little water will find its way there..if you have tile/grout check that.....check the tub strainer....kneel in the tub and see how tight the strainer ishow tight is the waste and overflow plate....these are all thing that will cause leaks....

Usually when this happens to me it’s the 4 inch line running from the shower valve to the tub spout. I think it’s all the back and forth flow it gets from hitting the shower diverter.

Like others have mentioned I’ve also seen tub spout diverters send water shooting backwards into the wall too.