Hello everybody. I have just moved to a new house which has a flagstone patio instead of the level concrete patio I had before. The tub is currently sitting on the patio (without water) and it rocks back and forth several inches.

Obviously, this is no good, so I am looking for suggestions on how to build a level area without destroying my flagstone.

I have been considering building a frame, lining it with plastic, then pouring concrete in this frame. If I ever wanted to remove the tub, the concrete slab could be broken up and removed without damaging the stones.

Is this a good idea? Anybody have any other Ideas?

If it's not too late, build a wooden frame, use pea rock to level it, and simply place the tub on the pea rock. It allows for drainage, easier to level, less costly, and easily removed.