Flooring Tile - help tile my floor PLEASE

I am redoing my kitchen - taking up the vinyl flooring and the subfloor, down to the original house floor boards. We want to lay 12 x 12 ceramic tile.

what kind of subfloor should I use for the new floor. Some have told me A/B plywood (but what thickness and should it be one layer or two - to make up the thickness)

but some have said to put down ply, then cement backer board -

the room is barely 15 x 15 with an L-shaped counter, a pantry cabinet and pennisula - so there is alot of cut to fit that will need to happen

-thanks for the help

What is the size and thickness of those floorboards and what size joists are they on, spacing of joists and length of unsupported span is needed too. Not that we are nosey but your answers will shape our answers. You will need plywood and cement board but we will get to that in a future post.

the flooring is tongue and groove with a subfloor under that - the floor joists are every 9 (maybe 12") the length is the width of the twin house 14'

i thought i saw in another post where they said to lay 3/4 ply (screwing into the joists and then a layer of 1/2 (screwing into the 3/4 only)

-thanks

-jim

You can get by with the 3/4" BCX grade plywood screwed into the t&g, then a 1/4" cement board set in a 1/4" notched trowel bed of thinset and anchored with galvanized hot dipped roofing nails. If Tileman or Tilebri see this post they may have more and or better info for you.

as it is now - I'm doing an archelogoical dig in the kitchen. The floor is 2 layers of linoleum, one layer of ply, another layer of linoleum, then a layer of ply, then the original flooring which seems to be just ply

there may be something structural floor under that (?)

is my next step to put cement backer ontop of the original ply or still put the bcx ontop the original ply?

-jim

How thick is the original ply and what's under it, joist size, spacing and length of unsupported span?:)

it is hard to tell what is under the ply - from the basement looking up it looks like tongue and groove - but it is just as well to put the new ply on - because the floor has a couple of patch jobs and the new floor is going to extend into the dining room that had TnG floor - so the new ply will give a consistant base for te backer board

- new question about backer board - there are some vents in the floor and some 3" deep notches in the wall - how do I place the backer board in these areas? do I notch the board or cut and place little strips or square in and around these areas?

-jim