Yes, you can lay new tiles over an existing floor tile surface using a good tile adhesive such as Mapei’s Keraflex or Keraflex Maxi S1.  This is provided the existing floor surface is sound and stable and there is no trace of hollowness in the existing floor.

No, tile adhesive is the product to bond the tile to the surface whereas tile grout is to fill the joints between tiles.  They serve different functions and thus have different physical properties.

Yes, you may refer to current updated standards such as ISO 13007-1 and BS EN 12004. You may also refer to our article “Understanding tile adhesives and its related standards”.

During the installation of cementitious grouts, the cleaning can be done with clean water.  When using strong colours of tile grouts, you may need repeated cleaning with new buckets of clean water and sponge.  For hardened tile grout, sometimes it may be necessarily to use cleaning agents with neutral pH.  Be careful not to use strong acids for cleaning cementitious grouts.

Although they both have similar functions to level the substrate, the selection on which to use will depend on the application.  Screed mortars are normally laid to receive tile and stone finishes and the mix consistency of the mortar is such that the application is normally done by hand.  The mix consistency of self-levelling products are more fluid and designed to flow and achieve a more accurate level to apply vinyl adhesive and receive resilient finishes such as vinyl, carpet and engineered wood flooring.