shower leaks through ceiling
I live in a 2 story condo. While taking a shower upstairs, water came cascading down through ceiling to down stairs unit. Tried to duplicate leak and could not.
1. tub spout turned on hot only for 5 min, no leaks
2. tub spout turned on cold only for 5 min, no leaks.
3. took off shower head and capped off shower spout, turned on for 5 min, no leaks
4. put shower head back on, got in shower, sprayed walls, jumped up and down around drain for 15 minutes, no leaks
5, cut holes in ceiling, sheet rock is wet, but cannot see any leaking pipes.
water stains on ceiling, indicating it has had small leak before.
no fancy shower valve, hot and cold handles, and diveter handle for shower. This is a tub and shower combo.
flushed toilet 20x just in case.
what would cause this intermitant leak??