I have installed ceramic, porcelain, and natural stone tile previously. In those cases, I also installed the underlayment, using 3/4" plywood (glued and screwed) and then 1/4" cement board (thin-set mortar and screwed).

I am now considering another tiling project in our bathroom. I was watching a home improvement show on television and they suggested the following as a "quick fix":

Install the cement board (with mortar and screws) directly onto vinyl flooring and then lay the tile on the cement board.

Any thoughts on this? Has anyone tried it?

I am worried about doing it because I don't trust any "quick fix" and also I have no idea what is underneath my vinyl floor.

It seems like a great idea, though, as it'll save on the cost and time of removing the old floor/underlayment and installing the 3/4" plywood etc.

This is acceptable but it is not the wisest choice. First we need to know what is under the existing tiles, there may already be a sutiable sub floor in place. I would advocate removing the vinyl tiles in all cases since they add to the floors height unnecessarily. Do you know for sure what is under the tile?

Do you know for sure what is under the tile?

Nope, I have no clue what is underneath.

I'm starting to think this makes a really great idea for a 30-minute episode on TV, but a really bad idea if you want a good-looking, long-lasting floor that does not have cracks in it.

Floor height is definitely another issue, although I kind of have a plan for that.

Thanks for your reply. You confirmed what I was thinking.

Yep, I hear you, it can get to be a real project quick. If you want to go further let me know and we'll figure the sub floor thickness and go from there. You already outlined the sub floors you did before and that is the accepted minimum.