There are numbers of reasons a tile floor may loosen,the most common of which are a floor expansion or shrinkage, Unclean setting Surface, Incorrectly or poorly mixed bonding mortar, Moisture, Incorrect Installation. This type of problem can be easily avoided by using proper total tile adhesive techniques
Generally this problem raise at wet areas such as bathroom, kitchen, swimming pools, water tanks to Avoid this problem, a proper waterproofing is must be done before tile installation to avoid PREVENTION IS BETTER THAN CURE Why because once it happen its difficult to identify where the leak is.Not only that to rectify this kind of problem take time and money consuming.
There are many reasons that tiles won't stay up. The plaster underneath Isn't primed, The tiles have not been cleaned properly, Adhesive is not been applied properly, Grouting is done to early, Incorrect Tile Grout used, Tiles have not been properly grouted, Tiles have not been left to set. This type of de bonding
If you are buying costly tiles and filling those tile joints/gaps with cement at joints then this problem will definitely rise. Cement is a high water and oil absorbs and non-flexible materials so it tends to crack and over a period of time it accumulate dirt and become smellu dirty jooints. This can be avoid by using spacer and applying Epoxy grout. Epoxy grouts are stain free, excellent water –resistant and maintenance free.
If your floor tiles are hollows sounding, you really do need to take some action.This situation will generllu become obvious in traditional or conventional tile installion method. Not enough mortar under the tiles, or 'dobbing' of the mortar under the triles. This leaves hollows voids, the wrong adhesive has been used andit has not bonded with to the tiles or substrate. Or, in wet areas, the adhesive is not suitable and has brokem down, The Morter has skinned before the tiles were laid. This means that the mortar was put down and left too long and the surface has dried. This prevents a sound bond to the tile. This can be avoided A proper application techniques with right tile adhesive back buttering on tile and surfaces.
It is hard to determine the exact cause of a crack without an inspection but cracks in tile can be caused by several reasons. Any movement in the concreate will cause cracks in the tile layer if the tile is bonded to the concrete. If cracks occur in the concrete, they will reflect through the tile, tyhis is called reflective cracking. This type of cracking can be easily avoided by a proper tile adhesive .