Marquina Polished Black Porcelain Marble Effect 60x120 Wall and Floor Tiles

Hi Aras, It is always best practice to remove any existing tiles. However, in the case where this isn't an option, you will need to ensure the existing tiles are fully secure, not loose or cracked and the grout lines need to be intact. You will need to sand the pre-existing tiles to create what is called a 'key' for the adhesive to adhere to. Then, ensure the tiles are cleaned thoroughly and free of any dirt or dust and you will need to ensure these are primed with a product such as Mapei Eco Prim Grip Plus. Kind regards, Walls and Floors

Hi Clive, These tiles are suitable for underfloor heating! Kind regards, Walls and Floors.