My bathroom floor had linloleum on it then some one put carpet on top.

Question

Now I want to put 12x12 ceramic tiles down. Suggestions?

Answer 1

You'll have to take up the carpet, and typically the linoleum/vinyl flooring.  Then prepare the subfloor before tiling.  

If it's a wood subfloor, it has to be stable - typically this means adding 3/4" *plywood* (not OSB or PB) underlayment, followed by a layer of thinset, and then cement tile backer board.  

For tile over a concrete slab, you need a smooth, flat surface.  Use self-leveling mortar (pours like a runny milkshake to fill in low spots), and then a crack-isolating membrane.

Once your subfloor is prepared, design a layout, mark guide lines on the floor, and start tiling.

Here's a great website with lots of *accurate*  info on installing tile - http://www.floorstransformed.com

In selecting a thin-set, spend the extra money on a "fortified" thin-set.  The final cost is only a little more than buying unmodified thin-set plus a latex modifier, and it's easier to work with (just add water).

One word of warning - do NOT use premixed "thin-set".  "Premix thin-set" is actually mastic, a water-soluble glue that will disolve if it gets wet, and has terrible durability. Mastic should only be used for wall applications (and even then, I prefer to use real thin-set mortar).  

Answer 2

linoleum sometimes has asbestos or some kind of chemical that is known to cause cancer so you need to wear gloves and a mask when pulling it up also there could be black mold so if there is mold it is best if you wet it down first before pulling it up so that the dust does not get into your lungs and fly around your house getting everywhere.  Always wear gloves and mask when doing this.