The shower drain which is centered has a 1" deep cup screen that drops in . Whenever the screen clogs the water rises in the shower pan and eventually appears outside on the stucco celling of building overhang. When the screen is removed the drain quickly empties the pan and the leak stops. The pan tiled surface is not cracked.
The shower is fabricated with the back wall tiled and has a framed-glass enclosure in front sitting over a tiled pan. The pan is a rectangular wall that's 5 inches high, and surrounds a 36"x30" step-on floor.. Three years ago, the enclosure and wall tile were replaced; it appears the pan was not replaced. Grout seals the floor tile of the pan to the glazed face of the tile on the 5" wall of the pan.

How can I determine which drain device is installed into the pan & base? The leak appears when drain screen in clogged so doesn't that suggest the drain-pipe connection is secure? Can I determine if leak is around the top of the drain device; that is, its connection to the pan (or to the base) ?
Maybe this is optimistic, but are there drain types which can be replaced from above or which allow the drain-to-pan connection to be re-sealed, secured or tightened?

Incidentally, can drain-to-sewer pipe connection be re-tightened without getting underneath the pan/base ?

thanks much for any response.

ted

Hello ted, it sounds like to me that your pan does not have a membrane on it and the corner of the shower probably has a hair line crack on it somewhere that allows water to seep through onto the floor beneath the base, sense it only happens when the pan fills with water. Take a flash light and check very carefully around the inside edge of the shower base to see if you can see any little crack on the tile grout lines. The reason I say that there is no membrane on the shower base is because the membrane would prevent any water from leaking onto the floor beneath the base. Get back to us and let know what you find. Good luck----Zeke