"Per manufacturer, it is not suggested placing it on a deck since it would need an even surface to maintain structural integrity. "
OK, So the place where I need to put isn't level. building it on a deck is my best option. I can build a level deck. And the surface drainage will still work correctly. If I build the deck inside of the Garage after the one end will be 6-8 inches smaller then the other to achieve a level floor. And to suggest I wouldn't be an even surface is crazy. So will it fit on a 12' x 20' concrete pad?