No, it is not advisable when laying laminate to “lay the floor through” between two rooms and thus over a doorstep. This is because the laminate swells and shrinks in different ways due to different temperatures and different humidity levels in the individual rooms. It is therefore advisable to leave an expansion gap between the rooms and in the area of the door. To conceal and bridge this expansion joint, there are profiles of various types and skirtings for the wall gap.