Do they live in Florida as well? If so, it depends where in Florida they live because of elevation issues. There have been several instances here in the state of fiberglass pools uprooting and coming out of the ground. If they're in a higher elevation area like we are, then it shouldn't be a problem. We have an 18x36 in-ground made of concrete blocks under marcite. It's been there since 1975 and still works great.