What type of adhesive should be used when installing 4" tile squares to the ceiling of a small, 32" x 32" shower stall. The substrate is cement board.

Thanks for the assist!

Jay Lorenco

Thinset Mortar , You Can Also Add Calcium To Help It Stick Better, Or An Old Trick Is To Use Bakeing Soda To The Mix, What This Does Is Pull The Moisture Out Of The Mix More quick, What This Does Is Spead Up The Dry Time, Less Tiles Fall On Your Head, Lol

Modified thin set from your local tile store
get r done