Not intending to hijack, but I have a very related question.
I'm building an expansion to my lanai and will be placing my spa in this expansion. The floor will be paver brick, but about 2' above natural grade. My house is about 3' above grade with the existing lanai 4" down from that. (Lots of fill dirt). We're in Florida, so no freeze worries.
Do we need any special footings directly under the spa? By my calcs, we're looking at less than 100 pounds per square foot, so I wouldn't think so.