How to Level With Thin Set While Laying Tile

Use the correct thinset product for leveling floors while laying tile. Depending upon the specific requirements of the job, use thinset mortar for small adjustments, medium bed thinset for slightly larger adjustments, thick-bed installation products for heavy marble, tile or granite, or mortar bed installation, which allows more leveling, but is more time-consuming. Always choose the thinset or mortar product recommended for the tile. For instance, marble or granite tiles require a stronger and thicker mortar application product than lightweight ceramic or porcelain tiles.

Obtain the right trowel tool for the application. Mortar trowels have differently shaped teeth and depths depending upon the type of bed the tile requires.

Spread the thinset mortar in an even height across the area to lay tile to the height recommended by the product. Work in small sections, as you don’t want the thinset to dry before you have a chance to lay the tile. Only mix the mortar needed for the first section. It's better to mix less mortar than more, as mortar hardens quickly. Working in a 4-by-4 foot section is a good place to start.

Use the flat edge of the trowel to smooth out the thinset. Make mortar smooth by swirling the trowel over the thinset until evenly applied.

Turn the trowel on its toothed edge at a slight angle and create a grain in the thinset bed. Avoid straight lines, as swirled lines work better and keep tiles separately adhered. For instance, in a medium bed installation apply up to 3/4 of inch of mortar and use a trowel with 1/2 inch teeth to create the swirls in the tile.

Place the tile in the area and don’t forget to use spacers between the tiles for even grout lines. Lightly tap on the tile on all four corners with the handle of the trowel. Place a level on the tile and check for level. When you have two tiles together, span the level over both of them to ensure they are at the same height, if not, lift the tile and adjust the mortar until they are level.

Repeat this process for the entire area that requires tile, laying down the mortar and then placing the tile following the steps accordingly. Allow mortared tiles 16 hours to dry before walking on them. If you can, allow them to cure 24 hours before removing the spacers and setting the grout.