Tile for thinset is like the wheels for a car: You can't install tile without thinset just as you can't drive a car without wheels. In addition to producing an uneven surface, applying too much thinset can create costly cleanup headaches and add unnecessary time to a project. Simple installation rules eliminate the possibility of this potential problem.
It is of paramount importance to install clay-bodied Spanish paver tiles with the proper amount of thinset. Tile-setters traditionally use a 3/8-inch trowel to comb this kind of tile onto the substrate in an even manner to avoid over-application of thinset. The application of excess thinset with Spanish pavers will lead to staining and uneven surfaces.
Glass mosaics are very thin, mounted on front-placed plastic or mesh backing; they do not install correctly when too much thinset is applied. Expert tile-setters recommend a 1/8-inch V-notch trowel thinset application in even strokes for installing glass mosaic tiles. When installing glass mosaics, excess thinset will bleed through the grout lines and create a disjointed, uneven tile project mess.
Natural stone such as limestone, marble, slate and granite must be installed with the appropriate amount of thinset. For instance, natural stone that lacks uniformity in thickness -- called "ungauged" in the tile trade -- require a thick or medium-bed thinset carefully applied with a deep-notched trowel. A lot of finesse and patience are required for installing ungauged stone. Thinner natural stones like travertine require a simple polymer-modified thinset and 1/4-inch notched trowel application. Applying too much thinset when installing natural stone will lead to a finished surface that lacks uniformity.
Ceramic and Porcelain
Ceramic and porcelain tile are properly installed with a tradition notched trowel at depths of 1/4 inch to 3/8 inch. The key with ceramic and porcelain tile installation is to apply an even amount of thinset under each individual piece. Excess thinset will squirt out of the grout lines and create unneeded hassle.