Flooring Tile - installing porceline tile

Hi, I am just about to redo my kitchen floor. It already has two layers of vinyl flooring on it - which I am about to remove. If I rip up the complete floor to the joyces and install 3/4 in plywood can I install my porcelin tile directly on top without using a tile backer since the 3/4 in plywood will be a brand new subfloor? Any recommendations would be appreciated.
thanks

Chances are you present plywood subfloor is fine and there is no reason to remove it. Doing so will just cause you more work and actually weaken your floor. Sheet vinyl is installed over 1/4" underlayment stapled to the subfloor. Simply remove the layers of 1/4" with vinyl attached. Then you will be better able to determine if an additional layer of plywood is needed. Tile though should be install over a tile backer or isolation membrane such as Ditra.

Tell me about the construction of the subfloor system. The size, species, spacing and span of the joists. What is the thickness of the subfloor sheet? I would also like to know what type of room this is and where on earth you are located.

Jaz

Thanks for starters - located in Ottawa,Ontario - hot summer/cold winter. The house was built in 1960 - the floor joyces are 16" centre. thickness of original subfloor is 5/8". What I am trying to achieve is to have the tile come level with the hardwood floor leading into the living room ( this is a kitchen btw). so I don't have to use a riser. That's why I thought about putting a new subfloor in to begin with. Also the tile that I am using in European porcelin tile which is very dense and heavy.
Kitchen is about 115 sq feet, room is almost totally square. joyces are 2x8 by 16 centre.
thanks - very appreciated

You cant set tile on one layer of plywood. It needs to be 2 layers totalling 1 1/4". That said though installing directly to plywood is the wrong way to go. Remove the vinyl and any 1/4" underlayments. If the 5/8" plywood is t&g you may be able to go over it with an uncoulpling membrane like ditra or CIS. These membranes dont add much height. You didnt answer all Jaz's questions regarding the structure of the floor. What is the size of the joists and what is there unsupported span?