Best Way to level grout under new composite tile

[worthy]

I'm covering a ceramic tile floor with composite tiles. The floor is level, the grout intact, but a mm below the ceramic so I have to fill the 5 mm wide grout lines or they will telegraph. Rather than using slc over the whole floor, can I level the grout alone with premix without removing the old grout first? Any other prep needed?

[cx]

Welcome back, Worthy. Please put a first name in a permanent signature line for us to use.

By "composite tiles" you're referring perhaps to vinyl composition tiles of one sort or another?

Do they come with installation instructions that might be helpful in determining what the manufacturer requires for a proper substrate?

I've not done much work with those tiles over the years, but I know some of them are very sensitive to lack of smoothness in the substrate. I can't imagine anything over a ceramic tile installation other than a self leveling cement being sufficient.

But let's see what others have to say.


My opinion; worth price charged.

[worthy]

Romastone by Chryntel is a marble and polymer self-adhesive 18"x18" tile. It's quite a bit thicker than the typical vinyl tile and is marketed as a "luxury" product.

The website instructions for the similar non-self adhesive tiles say that over existing ceramic or stone: "Floor prep requires the application of Ardex Feather Finish self-drying, cement based finishing underlayment or equivalent to the entire floor."

I was hoping for a simpler alternative. Guess not. Thanks for the fast response!