I had to add 2"x4"s to straighten the existing studs. I also added blocking.
The home owner has insulated the exterior wall which I'll cover with 6-mil poly.
I'll be hanging regular drywall panels on these walls.
WHAT?! ... regular drywall in a shower?!
Yes ... regular drywall in a shower. Kerdi membrane is waterproof and rated for saunas and steam-rooms. No water will ever penetrate the drywall panels and no mold will ever reside in these walls.
Things have a way of settling in these older homes.
You can see how much the original floor has settled in relation to the bottom edge of the drywall and by the space under my first 2"x4" placed for the curb. Here is an example of a shower curb requiring "mud-work" to correct the variances in heights etc.
The drain has been moved over by the home owner to accommodate the larger shower. I'll have to remove the drain assembly he installed because we are going to use a Kerdi drain for this project.
I'm using "Mortar Mix" to mud the curb.
The curb is now 100% level and plumb.
I'll build the floor with "Deck-Mud" and install the Kerdi drain next.
I've cut out the drain and widened the hole for placement of the Kerdi drain.
I've installed the Kerdi Drain with the flange about 1-1/2" above the floor.
Push and pack the mortar (deck mud) under the drain and try to level as much as possible. Keep checking all around the perimeter of the drain to correct loose areas until the entire ring sets firmly into the mortar bed.
So now back to the walls.
I've installed a piece of a plywood onto the back of the Niche .... in this case I was able to work from the other side of this wall which made it easy for me.
I've covered the 2"x4"s with scraps of cement board (mudded and screwed)
Ditra is fitted into the space.
The Kerdi installation is complete, and we're ready for tile.