Hello, I saw that my wooden floor was not leveled correctly (from highest point to the lowest there are roughly 14centimeters difference), so i started to remove the floor. I was stunned to find out that underneath the planks, the floor was filled with construction debris (around 4tons). After i removed the debris, i don’t know what would be the next step: how do i acually level this type of subfloor (i’m living at the second floor at this apartment) and then how do i insulate the floor (heat but most important sound insulation).
Here is a picture with the floor: floor
I forgot to mention that the room is 6.8meters by 4.8meters.