I purchased a new house 1 year ago in a somewhat wet area. The foundation seems ok a few small vertical cracks one larger than the others but Ithink it is ok. But my slab floor has sunk in spots up to 3 – 4 inches and has large cracks. Large enough to put a pencil through. My columns sank right with it and had to be dug up and re poored and the main beam leveled. My question is I think the actual foundatin is stable just the floating slab needs work. How would someone typically fix that.? Do you have to dig up the whole floor or can they cut and fix areas.??