Hi, I am remodeling my kitchen and redoing my floor. I will be using
12x12 porcelain tiles. I want to know what needs to go under the
tiles.

The contractor have removed the existing vinyl flooring with some kind
of backerboard, this is what I have now:

http://fenjing.smugmug.com/gallery/4460346_n85dF

I was under the impression the contractor will put weather paper, then
a layer of cement backboard, and then the tiles..

My question is, can the cement backboard (1/4 or ??) go directly on
top of this? Or do I need another layer of plywood board (how thick)
beneath the cement board?

I asked my dad (who is somewhat knowledgable but by no means a pro),
he said the plywood board is essential because the cement board is
brittle if lying directly on the wood beams.

Can someone help me? The contractor just started yesterday so I
haven't talked to him about the flooring yet. He did mention weather
paper and cement board. Should I insist on ? cement board if he is no
plywood is involved?

Thanks!

Raymond