My upstairs shower is leaking to 1st floor ceiling. Below is my troubleshooting:
* I tested by not using the shower for awhile, leak stopped so I know it's not from water line. * I had water going directly to drain pipe, no leak so I know it's not the pipes under the floor. * I took drain cover off and tightened the rubber seal around pipe on the flange thinking it was fixed. I let the shower run for almost an hour with nobody in the stall, no leak.

I thought it was fixed so I took a shower, it started leaking again. Leak is really slow as it takes awhile for leak spot to get wet. Seems like it leaks when weight is put on the base pan while showering. I'm hoping this could be fixed by replacing the drain flange from above (is that possible?) and not having to tear out ceiling or replacing whole shower stall along with the pan. speedball1 I've read some of your expert advise, should I be doing anything else to test? My friend thinks the base pan support may be broke so it's shifting when weight is put on it. I'm hoping it's just the drain flange seal. Help!