floor tiles

hallo all, first time on here.
my problem is, i have floor tiles in the entrance and then a lge hall and meals area then more tiles in a family room. we want to lay new tile over all these floors, so i am thinking instead of lifting the tiles already down. maybe i could just lay under board on the concrete floor in between the tiled areas and tile over the rest.
if so, what board do you use and how do you fix it to the concrete floor?

Hi There

Not sure if I followed your question correctly ... but if you want to tile a concrete floor, this should be possible (with the correct preparation) without need for any additional sheeting.