I'm in over my head. Please help.
For starters, everything I know about shower installation and remodeling I learned in the last 2 days. I started this thinking I was just finally going to replace an ugly river rock shower floor and bench tile that my wife and I have hated since we bought the house almost 10 years ago. Now I feel like I’ve opened pandora's box and have no idea where to begin.
The bathroom/shower has always felt a little humid and musty, but we never saw any obvious reasons or drainage problems. I decided to try removing the river rock and mud bed myself and worked really hard to preserve the liner because I thought I could just retile it.
As I removed the floor, I found black mold in several areas, especially around the drain. Some sections of the mud bed had already basically disintegrated/sloughed off on their own near the drain from chronic moisture, while other areas farther away were much harder to remove. I achieved my original goal by removing almost all of the floor without damaging the liner, listening to youtube tutorials as I worked, when I started noticing some things that seemed at odds with what I was learning:
Apparently there is supposed to be a pre-sloped mud bed beneath the liner.
Apparently the drain is supposed to have weep holes.
Apparently I knew absolutely nothing but now I'm wondering if the people who installed the shower knew as much as I do. (Maybe they did it right, but everything I'm reading says water shouldn't pool on the liner.)
The liner appears to sit directly on the slab completely flat. When I tested it, water from the faucet literally sat pooled near the curb area (blue circle in the pic) instead of draining, and it took 3 full days to dry. So unless I’m misunderstanding something, it seems like for years water was penetrating through the tile/mud bed, reaching the liner, and then just sitting there trapped with nowhere to go or dry out properly.
To make things worse:
I can’t identify any visible weep holes in this drain.
The drain appears glued directly into the slab pipe.
There’s no access from beneath the drain because it’s a single story slab foundation.
So now I'm weighing my options and not excited about any of them, least of all the one that involves hiring a professional because if we could afford it I wouldn't be bothering any of you fine people taking the time to read this.
Plan A) I remove the remaining wall tile without damaging the liner, leave the drain/pipe connection alone, fold up the liner enough to create a pre-sloped mud bed underneath it, lay it back down, then put down another sloped mudbed and tile.
Or
Plan 2) I try a Kerdi system thing but that seems to require replacing the drain entirely which I'm dreading due to the aforementioned reasons.
Or
No clue. Please help.
One last thing, not sure if I'm overthinking it. The guy who replaced the window a year ago installed it directly on top of the tile, which now seems like another problem waiting for me.
At this point I honestly don’t know the smartest path forward:
Try to preserve/rework the existing liner?
Full pan rebuild?
Kerdi conversion?
Convert the whole area to a closet and use the shower in the guest bathroom indefinitely?
How difficult is replacing a glued slab shower drain realistically for a fairly confident DIYer who's never tackled shower drains before?
Any advice would be hugely appreciated. I’m handy in general, but shower systems are obviously way more technical than I realized.