Has anyone ever had this done? My old house was built on stacked rocks. It is unlevel in places and at some point, a den was added and I think the den was added on after the house was already unlevel. At some places the roof line sags. I've had an estimate from a man who specializes in this. He said that he could re-level in 2 days. They would use concrete blocks every 6 feet. Just wondering if anyone has any experience with this so I will know if I would be satisfied with what i expect. My main concerns are: The roofline will still sag.....he says it will go right back into place. And, he says there is no problem with the den having been added on after the house was already unlevel........the house and den will all be the same height........I'm just kinda unsure on this. Its hard to do anything else with a house that needs doing when its unlevel...Thanks in advance.