I got an inflatable hot tub which I want to place on an existing concrete surface.
However, I am concerned about heat loss since concrete is a fairly good thermal conductor. I would like to insulate it as best as possible.
What is the easiest way to do this?
I was thinking of getting rigid foam board insulation such as this. I could get 1 or two boards and cut a circular pad, nicely matching the shake of the hot tub. Is this a bad idea?