How floor printing works
In floor mode the machine is set to run along horizontal rails laid across the area to be printed. Instead of climbing a wall, the printhead carriage travels the length of the rail while the machine indexes sideways, printing in bands exactly as it does vertically. UV LEDs beside the head cure the ink as it lands, so each band is dry before the next one starts and the printed area can be walked on far sooner than paint or a resin graphic.
The rails do two jobs: they hold the head at a constant distance from a floor that is rarely perfectly level, and they keep the geometry square so that a large graphic tiles correctly across many passes. As with walls, width along the rail direction is limited only by how many times you are willing to reposition the machine.