How does one insert a structural floor on a one story house on a basement? I’ve watched the videos and they keep showing a “Structural Floor” button. I may be an idiot, but I cannot find that button. I have a hardwood floor inserted, but no structural floor. I want to do a floor joist layout but cannot until I have the floor inserted. Please help. I need to do the roof truss layout as well, is it the same process?