QUESTIONBond Failure - a local contractor installed on the floor of my residence in San Diego a porcelain large size tile manufactured in Spain. He used a custom Building thinset mortar premium for Marble and Stone, from Home depot The whole job needs to be reinstalled as there was no adhesion between the tile and the thinset. The base floor is wood and has been reinforced prior to installation. The wood floor has been recover by hardibacker boards. What kind of thinset would you recommend for Porcelain Tile. (non porous)
ANSWERANSWER - Porcelain Tile should be installed with a latex modified thin-set or a polymer modified thin-set. The Custom Marble Granite Mortar I believe is a polymer modified thin-set. For larger tiles 12x12 or larger should use a 1/4" sq. notch trowel. Use flat side of trowel to spread first on subfloor then trowel with notch side in one direction "Only" then set tile into thin-set and move in a perpendicular direction to the trowel marks and push down to embed tile. Don't trowel too far ahead and make sure thin-set stays tacky.
If the thin-set did not bond to the tile, then either the thin-set dried too quickly or installer waited too long before embedding the tile into the thin-set, relative to temperature and absroption rate of Hardibacker board, and it skinned over and lost bond. Good Luck!