Take a look at the process of building a marble, travertine, or rectified porcelain mud set floor with Paradise Remodeling.
It all starts with clean builders sand and Portland Cement.
With cracked concrete to start with you MUST use a Crack-Isolation membrane.
One-at-a-time - 'thin-set' on the back of each tile to be laid.
Then 'thin-set' on the space on the floor where the tile is to be placed.
Portland and sand mixed 'damp' put over the thin set so everything bonds together.
Evening out the Portland and sand - The "Mud" in mud-set.
The Mud all leveled out ready to receive the tile
The tile is installed 'gently' then set down slowly with a rubber hammer or other device.
The excess Mud and thin set is removed leaving a clean edge for the next tile to begin.
The next day the grout is rubber troweled on.