Do you have the ceiling height to put in a subfloor? The subfloor would be warmer and not as hard as concrete.
There are cement products that will give a good level surface. Visit a home center.
Tile needs a very flat. smooth surface. Any imperfections will show through to the surface as bumps. You would be better off putting down 1/4 luaun ply, then the tile.
© 2016 Renovate Your World LLC