It depends entirely on whether the tile is in a wet area.
Dry areas (backsplashes, fireplaces, dry walls): yes, with Bond Plaster
Existing tile in a dry interior area can be plastered over using Earthaus Bond Plaster as the first coat. Bond Plaster is specially formulated to adhere to unconventional, low-absorption surfaces like tile.
The tile must be clean, degreased, sound, and firmly attached.
Once the Bond Plaster coat has cured, apply your chosen finish (for example, Stone Finish) over it.
Showers and wet areas: no — never
Earthaus plasters, including Tadelakt, must not be applied over existing tile in showers, tub surrounds, steam showers, or any wet area.
For a Tadelakt shower, the tile must be removed and the proper substrate built: framing, rigid 1/2" backerboard, ANSI 118.10 waterproofing membrane, and a modified thinset key coat.
Questions? Email [email protected] or text 1-800-917-2414.