In two frenzied nights of building I managed to frame up the entire halfpipe. It’s solid as a rock too. The flat bottom has 26 joists in a 6×8 foot area. That’s nearly solid wood. The transitions have quite a few joists as well, making them pretty solid. I’m almost considering adding one or two more just for the heck of it.
I’m going to be covering the ramp starting tonight or tomorrow when my brother gets into town for a visit. Before I do that though, I think I’ll take Matt’s advice and put some sound insulation in. He suggested foam egg crate, but I was thinking of using that 1" pink foam insulation that Home Depot sells. I can cut it to fit between the joists, and in the open transition areas, cover the floor as well. Before putting down the skin is the only chance I have at doing it, so I better decide soon, or resign to living with a noiser ramp.