After removing ceramic tile from a bathroom floor, I want to tile over it using 12x's marble squares. I was able to remove the old tile with minimal damage to cement (it looks like cement and wire lath.) My first question is whether I can install the marble tiles over the existing cement base, and if this is ok, my second question is what to use for some slight depressions in a few areas. In other words, would I use some sort of leveling cement or other? Thank you.

you are dealing with an old mortar and lathe job.

you need to remove the rest of the mess.
Get a sledge, flatbar, and a straight claw hammer, and remove the mortar and lathe.
Careful of the lathe, it will cut you.

I find the best way is to hammer cracks in a square of about two feet, then hammer the straight claw hammer into these cracks and through the lathe, cutting a square into the lathe. Then use a flatbar to lift the squares up and out of the room. A couple trash barrels will do you good. Don't overfill, and kill your back.

Remove all down to subfloor. And sweep clean.
You should install some sort of underlayment, whether its CBU, hardi, densshield, ditra, what have you. Then install tile using modified thinset. Wait 24 hours before walking, and grout. Wait 3 days after grout cures and seal.

good luck with your project

P.S. Remove the existing mortar and lathe before doing anything. Its work, but necessary. If you try and level it off and install tile, you most likely will get cracks and nightmares


Matt
Cupan Custom Tile and Paint
Charlotte, NC
tile contractor

Thanks for those tips, Matt but unfortunately your response came a little late for my floor project. I ended up using some stuff called Henry 547 Unipro to fill in the slight depressions and put a skim coat where I felt it was needed. Then, I used a medium bed mortar w/polymer to install the tiles. However, you have me concerned now. For future reference, could you tell me why you feel it is necessary to remove existing mortar and lath? Also, I will be using the same marble over Durock on shower walls, and would like your input on best method and if I could use the MBM to secure the tiles. Thanks.

Anyone care to comment?

I am about to remove the mortar and lath from a wall to replace a bathtub and then retile the wall using backer board and ceramic tile. I am afraid that there may be asbestos in the mortar. Any suggestions?

It's highly unlikely there's asbestos in the mortar. I've yet to ever hear of that EVER being used as a method for mixing mud. The only things that you'll find in that mortar are portland cement, lime, and sand.

Bill, thanks for the reply. I agree that it is unlikely that asbestos is there, but it is a major hassle to get anything tested unless you are on "This Old House". I am taking precautions nonetheless-face mask and wetting down the area before smashing the tile and mortar and prying off the lath. thanks-