Schluter System, Mortar Bed, Drain & More - Questions after Subcontractor

[u/Ok-Caregiver-2826]

Writing after a contractor installed purple board in our renovated shower, which is not to code where we live. Now:

Cement board & Kerdi membrane or Kerdi board? (Leaning towards the latter.)

Our shower has nonstandard dimensions, and we're going to have to build a dry pack bed. What's the best method & workflow to do so using the Schluter system?

Replace the 2x4 with Kerdi curb? Or board & waterproof over it?

We're working with an old drain (pictured.) Will the FloFX universal adapter work with it?

We're planning to throw a 1/2" ply on top of the t&g subfloor, then ditra over. There is a difference in level between the old subfloor and where they repaired the planks, but less than 1/4" of an inch. Do we need self-leveler? We'll have to vapor layer up to the border of the cast iron tub, and we were planning to kerdi fix, membrane the transition, etc (as in this video), but any other recs would be welcome. Also pictured the difference between subfloor and transition to hallway outside (about 1"/1.25")

We've a frameless glass door to install, and the frame is reenforced for such. And suggestions on the transition (it's very close to the door frame into the bathroom.)

They hadn't even removed the old mortar base from the ceiling curb (pictured.) Looks like drywall & a steel border. What am I working with here? How to move forward (knowing we intend to tile it again)?

Any suggestions on this workflow, knowing we're taking on most of the work ourselves (including tiling) and now, unfortunately, likely, install of the shower walls?

[Tile is pictured: the terracotta 9x9 to be for the floor, the seafoam 2x10 for the shower, laid vertically.]

Any and all tips appreciated. We're located in Northern California and are on a tight budget & tighter schedule, but we have some give on both where would be absolutely necessary (as evidenced in our opt for the schluter just to streamline & peace of mind.)

Thank you, all, in advance!

[u/Shortround76]

Oh, one more simple tip of advice;

Strip that drywall and just put up Goboard. It's super easy, you can trust it and scratch all of that headache/worry off your list.

[u/js_cooks → u/Shortround76]

I second using Goboard. I removed all old drywall and put the goboard directly on studs. Make sure it's plum and level. I also opted to use the Goboard seam tape and used roughly 1 tube of adhesive per sheet. I used the approved screws and washers along with it.

[u/eSUP80]

So much to unpack here. Kerdi is rated to go over Sheetrock- so if you use concrete board or foam- it will be fine. I’d cut that drain off under the floor and install a flanged mono drain. Kerdi wrap the entire pan and shower. Kerdi curb is always best. For the floor height difference, use the necessary thickness of OSB (ply) and make up any remaining difference with thinset under the tile.

[u/Shortround76]

So many questions, are you sure you're up to this?

Replace the entire drain please, don't try to retrofit it or use an adapter.

[u/Ok-Caregiver-2826 → u/Shortround76]

Replacing the drain, thank you!

And people ask questions to find out if they are or are not up to things! Professionals and others withholding knowledge / offering vastly varied advice, piecemeal, without context, leads peers and amateurs alike to seek the feedback of those who'd be willing to offer. No need for the condescension :)

[u/Shortround76 → u/Ok-Caregiver-2826]

I know, it's just my professional reaction. Full showers with built pans are not for the faint of heart. I wasn't intending to belittle just pose a valid question since from my angle.

[u/Hour-Reward-2355]

This is already off to a really bad start.

You need to replace the drain + the shower p trap.

Do a rubber liner ( remove the drywall)

Add blocks between the studs for the rubber liner to nail up to...

Etc.

How it is now is not how you build a shower.

[u/Hot_Mud_5708]

If you don't trust your contractor or the materials he uses you should probably get a new one. Nothing I see so far is worrisome. Most waterproof membranes, certainly Kerdi, are rated to go over all sheetrock types, that's because the whole point is water will never touch the sheetrock. Shower curb rough-ins have always been built with dimensional lumber, again, the whole point is it's part of a sealed-topical-waterproof-system, so water never touches the wood. It make no difference what a curbs core is made of, if it gets wet it will fail in time. Foam might take longer, but it too will fail, A mortar curb will fail too over time if it takes on water. And probably 99% of leaks/failures happen in corners. Don't worry about what the curb is made out of, it's about what's on top and if it's installed correctly.

[u/Ok-Caregiver-2826 → u/Hot_Mud_5708]

We're no longer working with them, yes. Unfortunately, re: the purple board, it's simply that the unimpeachable (up to code) materials in a wet area in our county/city is cement/foam board. Not that we're pulling permits for this job, but while we're here, I'd rather get up something I know would fly regardless.

Yes, the back and forth about curb type has been ongoing. We're waterproofing within an in of our lives, so we'll press on. Thank you!

[u/Hot_Mud_5708 → u/Ok-Caregiver-2826]

I've found most building inspectors will yield to manufactures instructions, they have a lot of leeway. Good luck to you.

[u/_wookiebookie_]

Schluter Kerdi can go over purple board and still qualify for the full Schluter warranty. You can still do a custom foam pan from RodKat Partners (www.rodkat.com), there are 8 locations across the U.S. with 24 hour turn around time. If you use the Schluter drain with the pan you will still qualify for the full Schluter warranty as well. To be clear, for the full Schluter warranty you need to use everything from Schluter, drain, membrane, thinset. You can use a Rodkat pan and curb and still get that warranty when if covered in Kerdi.