I have a 3.5' X 5' space in the basement bathroom where I want to install a tile shower. There is a brand new 3 piece shower drain there right now that is flush with the concrete on the bottom of the drain. The concrete already has a slope in it to the drain that starts out at about 1/4" bubble on my level but the last foot around the drain it steeply drops into the drain.
At the furthest wall it's 2 1/4 inches higher then base of the drain. From that wall it's 5/8" drop at about 26" inches then the last foot the bowl makes the last 1 5/8" drop is all in that last foot around the drain.
Is that steep bowl around the drain too much of a slope to make this work right with the membrane layer? can this be even out with the bed above the membrane? or do I need to *gulp* jackhammer and level the floor then do the preslope layer etc etc.
If the drain is not adjustable to raise the top of it, then get an upper piece that is adjustable and put it on your "3 piece drain".