When it comes to setting tile, be sure to choose the right trowel for the job.
Tile mortar trowels have notched edges. When held at an angle and passed over the mortar bed, they leave uniform rows or ridges that collapse when the tile is set in place, ensuring that the mortar makes uniform contact with the underside of the tile.
Hold the trowel at about 70 – 80 degrees and draw it so that you hear a scraping sound when doing the final run. You only want to leave behind the exact amount of mortar that the trowel was designed to leave.
So, what’s the correct notch size trowel to use? The minimum: quarter-by-three-eighths-by-quarter trowel to install a twelve-by-twelve tile.
When you get into the larger formats like a sixteen-by-sixteen, you’re going to want to switch to a quarter-by-half-inch-by-quarter-inch trowel. The round U at the bottom leaves a ridge that’s rounded so that when a tile is pressed onto the mortar, the lines collapse more easily because they’re rounded and there’s less drag and less resistance.
For very small tiles, a three-sixteenth inch notch trowel like this might very well be the best choice.
And finally, a hand-made trowel. You can make this trowel by using an angle grinder and an old diamond blade. You can actually make your own hand trowel to get into nooks and crannies where you might not be able to get with a large trowel.