In preparing for ceramic tiles, I've installed backerboard on three
shower walls to within 1/4" to 1/2" of the existing painted, sheetrock
ceiling. The question is, what to do with that gap. Possibilities:
1. Leave the gap empty (think of it as an expansion gap) and simply
cover gap with the ceramic tile to within 1/8" or so of the ceiling and
2. I could fill it with caulk, then cover it with tiles as described in 1.
3. Treat it like the other joints between backerboards and tape it and
cover the tape with the thinset. Will thinset adhere to the painted
ceiling? (I'll roughly sand it first to kill the gloss.)
Thanks for you suggestions. Please also email them to me, fixing my address.