Can I install Kerdi board just on the walls of my shower and use a PVC membrane on the floor?

Question

I have poured the preslope on the cement floor, and installed the Oatey PVC membrane and 3 piece drain.

I would like to use Kerdi board on the walls, but not the floor. Can I install Kerdi board next on the walls bring it down to the membrane?

After the Kerdi goes in, I would pour the final slope for the shower floor and tile overtop.

I like the Kerdi product for my walls because of the pre-fab niche, and lightweight materials and smaller board sizes that are available. I really don't see any videos of people installing Kerdi board with an Oatey membrane. Are the two incompatible for some reason?

Answer 1

That makes sense the installation video from Oatey says "wateproof drywall or cement board" but your kerdi board is waterproof too, so it's equivalent.

Be sure not to screw through the shower liner--if you need to screw low on the Kerdi board put a dwang (cross-block) in above the liner and screw to that.