How do you tile bathroom tiles on top of original tiles?

They say.
"the best surface to tile on, is a tiled surface." This is very true and the results will be better the the first layer. As TBird states use of normal tile will be good and will stick better to tiles that to a plastered surface. Just clean well before you start.

Simply Build Better
December 2007

Just clean any grease off the old tiles then use normal tile cement for the new ones. It may take a while to dry but when it does they should be fine.

Tbird
October 2007