Can you tile over 1/2" of drywall mud?
Let me try to explain my situation. We have an L shaped run (93" x 228"). The walls meet at an angle smaller than 90 degrees because the first stud out from the corner along one wall apparently bowed outward prominently. If we lay a long level and an angle, the gap at the corner is as big as 1/2 an inch. The walls have been primed (over existing paint) around this area.
We plan to do tiles (e.g. 18" x 18") up to wall cabinets along both walls, so the tiles will meet at the corner. If we don't do anything, and just grout under the tiles, we will have very thick grout at the corner and the ledge above the tiles will vary in thickness a lot.
We could apply thick mud at this corner to straighten out the angle to the height of wall cabinet (54" off floor) and then feather upward. We will prime and seal the mud. My question is : when we put the tiles up, will the thick mud be strong enough to support the tiles?
I guess maybe I should step back and ask a basic question: How would you prepare a severely wavy wall with cabinets already in place for tiling (with large tiles)?