A 3 8 x 3 8 trowel will leave a 3 16 bed of thinset beneath the tile.
Thinset thickness for large wall tile.
Jun 11 2011 the thinset thickness is determined by the size of the trowel used and the size of the trowel is determined by how the back of the tile is constructed and the size of the tile.
Mapei large format floor tile 50 lb gray powder thinset medium bed mortar item 1103731 model 2184323 good adhesion for ceramic porcelain and natural stone tiles with one or more sides greater than 15 in.
So a 3 8 u notched trowel leaves a 1 8 bed of thinset beneath the installed tile.
Using a u notched trowel and embedding the tile into the thinset leaves you with a bed of thinset beneath the tile a little over 1 3 the size of the trowel teeth.
Many thinsets max out at 1 4 in a single layer.
In the case of travertine the back of the tile is smooth so a larger notched trowel wouldn t necessarily be required.