Once a hot tub is delivered to the original buyer, it’s intended to sit there for the rest of its life.
Once the packaging has been removed mother nature and wear and tear begin to work away at weakening the frame and cabinet, and sometimes moist insulation (often from leaks) and residual water in the plumbing make it way heavier than what it was when it came of the truck the first time.
Every so often we come across a hot tub that looks to be in good condition but will no longer support its own weight on end. Since it’s almost always necessary to put a hot tub “on end” for delivery, we always inspect the frame and cabinet for structural integrity.
the only way to know for sure is to lift the tub up to see underneath it, but if that’s not possible, poke all along the bottom rail in contact with the ground with a screwdriver to test for soft spots.