Generally, it is recommended to use normal or fast setting adhesives. However, always consult your tile merchant for detailed advice and always follow the manufacturer’s instructions.
Mix the adhesive as per manufacturer’s instructions and spread with a notch trowel. Place each tile into the adhesive firmly with a backward and forward movement to ensure a solid bed and to prevent any voids under the tile. Be careful to remove any surplus adhesive from the surface of the tile and joints with a damp sponge/cloth.
Work in small areas of about 1 square metre at a time so that the tiles are fixed before the adhesive forms a skin. Occasionally use a spirit level or straight edge to check that the tiles are flat. If needed, remove and adjust the amount of adhesive, being careful not to leave it too long or the adhesive will set.
Note: Lippage is inherent in all installations and may be unavoidable due to tile tolerances.
To prevent the chance of disturbing the bonding process, do not walk on or grout floor tiles for at least 24 hour, unless a rapid set adhesive has been used.
Source: Australian Tile Council website