"... I actually did not go with a 64 or 66 inch radius, instead I went with the plan [ RPDO ] had in the works for a 72 inch radius. " [ Chris Peterson, South San Francisco. USA ]

RPDO: This picture of the framing of Chris' ramp shows one way to build a ramp in sections. You'll notice that there are only four pieces of plywood used to form the three sections. While this is cheaper it has forced Chris to offset the joists in each section. This makes it harder to determine where the joists are when screwing in your surface. Every layer of surface needs to screw into the joists, so it's best if you can just run a chalk line from one side of your ramp to the other.

Our advice, build your ramp in separate sections mark where the joists go on one template, and use that template to mark the others.