diagnosis of bathroom ceiling leak

[cycjec]

Water was leaking from upstairs bathroom into the one below. We ran the shower/tub water, the sink, the toilet. No leak. The plumber thinks it is because of defective caulk in the tub. I hope he is right.

[willshak]

cycjec wrote the following:

It can also be from the plumbing in the wall.

[bob haller]

or the weight of standing in the tub causing the leak.

if caulk does not fix it tear down the cieling and take a look

[jamesgangnc]

Is the upstairs bathroom used regularly? If so the caulk is a possibility.

[krw]

Yep. I had that problem in my previous house. I couldn't find the leak until one day I decided to look (I had the ceiling torn out already) when SWMBO was taking a shower.

[RogerT]

Or, from where the shower faucet(s) go through the wall if not caulked well. Or, from the tub overflow, if that connection is loose.

[Tony Hwang]

Hi, Did you use coloring agent when checking?

[bob haller]

the best way is tear down the already damaged cieling, it may uncover more than one issue........

[jimmy]

[cycjec]

Yes. But the leak doesn't seem to correlate with usage. It happens at odd times.

I think everyone is right who said "take the ceiling" down.

[cycjec]

An excellent idea.

[cycjec]

The plumbing here has had several half hearted repairs by the previous landlord. [One of these involved wrapping a pipe in blue goo; I demurred and was told to mind my own business]

Thanks to all who replied.

[Evan]

When you check for leaks in a shower or tub you have to duplicate the usage pattern...

Just running the water won't tell you if the leak is coming from there...

~~ Evan