I'm curious what types of flooring you do use over slab then? I did tile over ditra in my master bath, there weren't any cracks in the slab, so I'm not worried about it cracking in there, did it mostly for waterproofing and a tiny bit of thermal insulation. I do still have about 1200 sft of slab floor that will need to be redone in my kitchen/dining/laundry/living area. I know I don't want to tile all of it, maybe none of it, but the best I can come up with is luxury vinyl planks (it needs to be waterproof, not just water resistant). Problem is the floor needs to be relatively flat and I can't use any underlayment with that stuff apparently. I'm confused why LVP doesn't allow underlayment when laminate planks do. I could just do LVP in the kitchen area and stick with carpet in the living area, but really would like to ditch the carpet. Large area over a likely unlevel and cracked slab is a problem though. I'm surprise there doesn't seem to be better options.