Can ceramic tile be installed on top of ceramic tile?

Question

The old tile is a ca. 4in square tile with scrolled edges, and the new tile is to be 12x12.
Does the old tile need to be scarfed (roughened up), and is there a chemical that does this?
Please answer only if you have done tile on tile installation successfully. THanks

Thanks for both answers, but it was not what I was asking for: You both so far gave me guesses, neiher of you gave me what I asked for: Please answer if you have done a successful installation of tile upon tile before.
My concern is with making the new tile adhere sucessfullly to the old tile. Given the fact that the old tile has been in place for quite some time - and I should mention that it exhibits NO problems of cracking or anything except that the visual appeal lacks..

Answer 1

The answer is yes, however in order to get the new tile to adhere to the old tile the old tile must be "etched". Is the old tile shiny? If it is shiny the thin-set mortar will not stick to it. You can take a grinder to it and cut criss cross lines in the old tile to reveal the clay. the thin set mortar will stick if you do this but the process is very very dusty. The only other concern is the finished height of the new tile. Good Luck, and yes i have done this successfully more than once.

Answer 2

You should not install ceramic tile over ceramic tile, the very nature of the tile is uneven and if you install ceramic over it, it will crack the new tile. There is no other way to install new tile than to remove the old down to the subfloor and put down the new. However, you do have an option. You can epoxy coat the old tile and give it a brand new look if the tile is in good shape, that means no cracks in the tiles and all the grouting is solid. If any tiles are loose or cracked, its not that hard to remove. But if it is in good shape, first use a good detergent to remove the grease, then you can use muriatic acid (make sure the room is well ventilated) to score and pit the tile so that the epoxy will bond well. If you are just tired of the color of the old, I highly recommend picking up tub refinishing epoxy, you can add a bit of tint to it and you'll have a nice new looking floor. You can get the tub epoxy at any full service hardware store. Follow the directions exactly! Clean and dry the floor, prepare with muriatic acid, (directions on the bottle of acid and also in the tub epoxy instructions) wear gloves! Once the recommended time has passed for scoring the old tile, then wash it with lots of water, make sure there is no residue, then let dry for 24 hours. Mix the epoxy and follow the directions. With a little time and patience, you'll get the job done right. Just a thought....

Answer 3

Yes, just scrub to old tile to make sure it's clean