WHAT'S THE DIFFERENCE CONCRETE SLAB VS CONCRETE FLOOR? A concrete slab is poured right on a gravel pad and the edges are formed with 2x4's, 2x6's, 2x8's etc. A concrete floor is poured inside a concrete foundation, ICF walls, cement block walls, I think you get the idea. I'll tell you what I include and don't include in my concrete slab prices and give you an idea of what the extra cost is for some of the things that aren't included in the regular concrete slab cost.