Good evening, For any building you are designing, for example, I am using a single foundation. After removing the basement curtains from the foundation, I want to create a ground floor slab (it may not be curtains, but it is not so important). But at this point The program perceives all the floors I enter as rafts.Do I need to define a basement floor under the ground floor up to the foundation depth level for a modeling like this?Or briefly, how can I define a ground floor floor slab with a thickness of 12 cm (for example) above a single foundation? Thank you,