Ok we didn't have a choice, we demo'd the master shower. Now that we are putting it all back together, as a tub/shower we noticed a huge problem & I would love to hear any advice ya'll might have. The air stack between the 2 bathrooms has a joint that sticks out about an inch beyond the studs. The previous solution to this was 2 layers of sheetrock. Now we do plan to tile the surround, but would not like to have the alcove to be different dimmension than the rest of the room (it's a tiny room). So what do we do? The stack is cast iron & isn't gonna budge. My guess is to shim out the whole wall to fit around that joint. Any other ideas?