This would be around the bathtub area. Not sure whether to use the same cement board tape and mortar at the ceiling line or to switch to regular wallboard joint compound. Which is correct? Thanks!
Cement board is not normally used as a finished wall surface. But I guess you can if you want.
Youve got the right idea. It's called sanded caulk and it should be available in a color that matches your grout. Just be sure the bottom of your backer board is inside the lip of the tub and 1/4 above it so it won't wik moisture. As far as the why, it's mainly cosmetic. Good luck
i think most of the time the boards come in a dimension that puts them below the ceiling line and the difference is filled in with water resistant drywall and finished regularly, then most of the cement board is covered in tile so little finish work is needed on it .. if its all the way up probably just tape it and finish as normal but strictly speaking, the whole layout isnt correct if it terminates at the ceiling joint ..
If your tiling the ceiling you can use thin set to tape that corner joint. If you were not tiling the ceiling it d be different. Any questions you can email me through my avatar and check my qualifications there. GL
