Each night the tents were on sandy gravel but no ground cover. But, the floor of the tent/vestibule was fine, it was just the condensation from above. I'll try to get a photo posted.
The floor will always be fine. All the vapor will rise and condense on the fly. If you're talking about the outside of the fly, that's dew. The inner side, that's vapor from the ground and from you, combined with any humidity.
I've actually had horrible condensation on an open tarp suspended eight feet on the ground - the only time I've ever seen that with my tarp/hammock, both sides of the tarp were wet, was in Lyell Canyon camping on a bench off the trail and slightly up from the river. The ground is boggy and soaked in the lowest part of the canyon. Conditions were evidently perfect - if the ambient temp is just so, and the air is humid, it doesn't matter what the heck you do. All of us, tarpers and tenters, had horrible condensation. All the many other nights I've used a tarp I had zero issues, even camping next to streams.