We're about to remodel our bathroom, having tile applied to about 17 linear feet of wall (8' high). 90% of the wall area to be tiled already has green drywall. The remainder is open studs, where a bathtub used to sit. The tile contractor suggests we rip off all the greenboard and they will put up 1/2" kerdiboard instead.
I was thinking to fill in the missing greenboard (about 16 ft2) and the installer would put membrane over the whole thing.
I understand that either way will work.
It seems like it would be cheaper to go greenboard/membrane. I'm doing the drywall work (ripping off or installing).
Which is preferable and which would you do??