My upstairs bathroom floor needs to be tiled and my Husband and I have done a downstairs bathroom, but, he is wairy of doing the upstairs himself because he has heard you need to do some things differently and isn't sure of exactly what that entails. He is also nervous about not doing something right and having more ceilin leakage. We did have carpet in there (gross) that I pulled out so we only have the basic plywood subflooring, and I cannot seem to find any books or information that specifies a difference in tiling an upstairs bathroom as opposed to a downstairs bathroom...

Can someone please help me... Thank YOu

This isn't a difference, use durock concrete board or hardi backer, for the subfloor under the tile, this needs to get screwed down or nailed 1 3/4 ir 2" wil be fine,also they spaceing of the screws or nails should be around 6" square and on each edge of the board, after this lay your tile,