In the fall of 2001 I realized I had a skill saw and could build a ramp. I got a VHS from Thrasher Magazine that showed how. I built an 8' wide 4' high (height of a 1/2 sheet of plywood) 6' radius 1/4 pipe in my driveway. It was a lot of fun for me and our kids so in the spring I raised it 2" on 2x4's and extended it to a second 1/4 pipe with a 9'6" radius (having never skated different radiuses I wanted to try both). The sides and tops of the transitions were 3/4" pressure treated plywood. The 2x4's on the transitions were 10 or 12" on center - you cut them down from 96" (8') to 94" so the 8" plywood sheets will be 1/4" wider on each side and shoot two deck screws through the plywood into each end. I used regular 2x4's going down the transition until I got 8" or so from the ground, then I used pressure treated all the way across to the other transition. As I went from transition to flat I cheated and went to 14" or maybe 16" on center since there's not much force on the flat. I covered it with 2 sheets of 1/2" plywood, regular on the transition, pressure treated on the flat (should have used all pressure treated - not a major problem but would have been better) and covered it with 1/4" Masonite. Used solid exterior stain on the transition sides & top and exterior latex (same colors as our house) on the Masonite. I let the kids draw whatever they wanted on the side you couldn't see from the street.
I used plastic tarps with small bungee cords into clips screwed into the transition sides and snaps screwed into the flats to cover it up when not in use and when there was snow. That was a pain and water got under it on the flat from snow melting. Skatelite would have been a lot better and maybe caulking all the sheets on their perimiters. Water got between the sheets - mostly on the flat. I got that about 8" wide black plastic in a roll that you glue down on a roof edge and glued it on the flat then over and down the sides of the flat so it covered the 3 layers to keep the water out of the sides.
Had a lot of fun with the kids skating, playing hockey with a ball (the ball rolls back down after going through the goal), playing with cars, all sorts of things you'd never think of. Had it up for 9 years. Took it down but kept the wood - I always knew it would make a great shed and a couple of years later it did. Everything but a few rotted pieces was re-used. I re-used all the 2x4's in the walls although it would have been easier to use new - the old were so hard that I had to pre drill all the nail holes into their ends. The floor joists and roof rafters are new, the roof sheathing is from the transitions. You'll see in the shed floor the unpainted transition piece I had cut out and kept is reunited with the painted piece. The attic floor is the Masonite with the drawings on it. The shed door handle is a skateboard truck and the sliding door hangs on skateboard wheels, the ones with magnetos in them so they light up when they roll, so all those memories are alive in the shed.