Hi, we are putting tongue and groove ceiling up in a section of our house so we can blow insulation in. My problem comes in the master bathroom, most of the ceiling in there is the pine except for the area over the walk in tiled shower. The ceiling will eventually be tiled. I need to know what to put on the ceiling. Do we go right up with cement board and have that hold the insulation up? Do we use plywood and then go over that with the cement board? greenboard drywall and then the cement board? lol any help would be appreciated. I do want the least bit of difference between the final thickness of the shower ceiling and the pine that I can get. the pine is 3/4 thick.
As long as your ceiling framing is 16" OC or less, then use 1/2" Hardibacker with the tile fastened to that. If you have any doubts as to the strength of the Hardibacker, then add is some bridging between the joists in the shower ceiling area. If the framing above the shower is greater than 16" OC, then by all means install some extra bridging.
With 1/2" backer and tile, your finished level should be about 7/8"
