What kind of substrate, if any, do I need for putting ceramic tile on cement foundation?

Question

Here are the levels of flooring...ceramic tile, linoleum, then a red rubber type material that is in 12 in tiles, then the concrete foundation, or slab. We took everything out down to the cement. Do we need to put some other kind of substrate down before tiling? How do we prep the floor?

Answer 1

What sort of floor is a cement floor? It would be very unstable and dusty Cement is a powder . I do not understand

Answer 2

no substrate is needed to tile over a concrete slab.  the only prep really needed is to use a mesh tape and thinset to fix any cracks in the slab.  you can buy mesh tape at a hardware store.  skim a layer of thinset over the crack then place the mesh tape in the thinset.  smooth with a trowel/putty knife.  don't waste your money on any type of self leveling agents.  they don't work as advertised.  a good installer would be able to fix any low, unlevel spots as he/she is actually installing the tile.  any major high spots would have to be ground down with a concrete grinder, but a good installer would be able to work with that as well, if needed.  use a tile to linoleum transtition strip between the materials.  i'm not sure what the red rubber material is that you are referring to, so i have no advice there.  good luck!