Plumbing question
 

I have water damage on my living room ceiling. It’s a perfect circle right below the drain in the upstairs shower. I pulled a bunch of goop out it but can see water where the pipe turns. We haven’t used the shower in a month. My guess is the leak is where the drain cover rests on the shower floor or where pipe meeting the floor.If it was in the pipe below, I would think the pipe would have drained. Not being a plumber, I would think it would have drained.
Any thoughts appreciated.

Are you sure it’s the drain? Could be a supply line to the shower. I had a copper pipe develop pin hole leaks . Showed up on the downstairs bedroom ceiling.

If the spot stays wet it's likely a supply. Dry, probably the drain.

If you see water in the drain, that's likely the trap and it should hold water.

First I'd check and double check grout and caulk, then I would cut out the drywall and do a visual, with the shower on.

Depending on the age of the plumbing it's possible a metal trap has a corrosion pin hole . It will leak down to the point of the hole and then stop if additional water isn't added .

You don't want to hear this but the first thing I would do is to cut out the wet spot, about 16" sq and see what's going on. There's no magic fix. Something is leaking. Like Dad911 said, if it stays wet, then its a supply line, if not, its the drain or a broken pan. Open up and see. Run water to see it drip. It can also be the corners of the shower too.

yup. cut the the drywall. survey.

I had a similar issue at a rental.

One plumbing company said it was the bath tub’s overflow drain leaking, they sealed it and charged $400.

Sent a Second plumber to give a quote to change the tub, he found a supply leak.

Fixed the supply line, so far so good. (Got a partial refund from first plumber for misdiagnosis)