thanks, I put spruce-pine-fir, 2x8, No.2(I assumed), floor joist, L/720, 16"spacing in the calculator. it give me 9"9. looks like it is not good for marble. My current is 4 layers vinyl, they stick very well. does this help for marble?
My plan is put a layer of mesh net and staple them, then apply motor for marble? if this is not good for marble, I will just go with ceramic tiles.

Before you do any tile installation those 4 layers of vinyl and the underlay must go.

The mesh net you are referring to, is it Mapeilath plastic mesh or are you talking about galvanized wire lath? If it's the wire lath /scratch coat then that's garbage. Go to the Home Page and on the left side there's an article About Scratchcoat. http://www.ontariotile.com/scratchcoat.html
Take a look at it, then decide if you want to risk an installation with that method.

I am lucky I asked here before apply mental lath. I learned the lath way from my neighbour, their contractor just finished their new tile floor with lath over the viny floor. But even in Rona, it is called "lath floor galvanized".
In Rona, I also saw a "synthetic lath", is that good for flooring?

And what kinds of choices do I have over the vinyl floor,
1) put a cement board or underlayment wood over vinyl and screwed them?
2) Ditra ?

You should heed RC's advice and get rid of all four layers of vinyl. You don't really know what's underneath them, and that many layers is bound to have some cushion to it. Better to put the effort into removing it now, rather than just going over them and causing in installation failure.

Looks like I cannot avoid that job. :-(. thanks for help.

I read the "tile installation" pages in this website where it talks several substrates. I am confused after read mud and scratchcoat. In "mud", it said "Mental lath is used to enforce the mortar bed.". In "scratchcoat", it said "This method is meant only for walls." So, mental lath and wire mesh are different stuff? what's the different between these two? thanks

Metal lath,expanded metal lath and wire mesh refer to the same type of product. The differences are in the size of openings and the thickness of the mesh. It is made up of sheets that are slit and expanded to form small diamond shaped openings.


Mud and lath is mostly used for doing walls,as you saw in the tutorials.