All the tiles and around the tub are sealed up well and still water leaks through to downstairs. The pipes were checked , etc.
Does grout eventually let water soak through after a certain time goes by?
Thanks.
John .S

Is the grout intact? Can you see any cracks? How were "the pipes checked "? Did they open a wall or ceiling? When were the walls last regrouted.

While grout doe not wear out and leak it will shrink over time and allow water to get past the tile. The solution would be to regrout the section the shower stream hits. Good luck. Tom

Without better investigation its hard to tell if you have bad grout or a plumbing leak. Chances are very good it's a plumbing problem. Is this a tub w/ shower or a free standing shower stall? Does it only leak wjen showering?

The grout is all intact with one or two hairline cracks. It's a shower head, knobs, and
Regular sized spout, but a small "bath tub". Regular depth but too short to bath in.
There's a curtain which I keep sealed to the wall with Velcro type stripping from the
Dollar store so the floor is always dry after a shower, but with the ceiling opened up
Downstairs, the pipes have been closely inspected by observation while I was taking
A shower, or just running the spout, or shower head with only cold, or only hot water
Etc, and I'm told that it's leaking down through the wall to a spot aligning outside the
Tub but not from the pipes, so it's thought that I soak the floor and it somehow seeps downstairs through the tiles. Upon close inspection through the hatch in the adjacent closet (which I had to empty 3 times) the pipes, and connections,were always bone dry. At first I thought it was the drain somehow, but that's not it either.
Sections of the wall tiles have been re-grouted at different times but the tiles which
Are suspect have been done within the last month and through trial and error there's still water going through to downstairs. More than ever.
Thanks, Jnu7

The wet ceiling needs to be removed, once it's repeatedly wet you can't save it. With the ceiling out you will be able to better see. Try filling buckets elsewhere and then dump in the tub carefully not splashing. This will test the drain.

If you can get a hose into area,with someone down stairs,start in tub and run water for about 2 minutes. If no leak move up to top of tub and repeat. Do this at each line of tile and you will be able to localize the spot where tile is leaking.

Chuck