The walls

Now prepare a solution for screed from cement, sand and sowing. You can use only a freshly prepared solution for filling. Lay waterproofing around the perimeter of the room so that moisture from the solution is not absorbed into the walls. And start filling. Make sure that the top of the screed is as even as possible and has a difference in height of not more than 2 mm per square meter of area. Then stop working until the screed is completely dry. Now you can lay for example a floating floor if you want to warm it or some other heat-insulating material. Further, also collect a wooden floor in level and you can lay a laminate.