Posted: 25/04/2015 at 10:08
Chocolate vine's a twiner, not a clinger. It'll happily enough climb the shed if you mount trellis on spacers or provide wires. Simple enough job to put a trellis up 2" off the shed wall, but putting trellis over the roof without piercing the roof could be a bit trickier. You'd have to mount short legs on the gable ends, rails between them and the trellis on the rails, and I think the trellis would sag in the middle if you didn't give it enough rail support. Could be done, but isn't trivial.
Virginia Creeper and Hydrangea are both clinging climbers, so they'll cover a shed. You just need to occasionally get them away from the windows and door.
One of my hydrangeas has found itself in direct competition with a sycamore ... and its response has been along the lines of: "Nice structure. I'll take it."
Final height of that plant is reckoned at 15m, so that tree is not too tall to eat.
Alternatively, there's the "heap of rose bush" approach to covering a shed:
See the shed? There's a shed. It's about 10 x 7 x 4 metres, accessed down a ramp on the far side of that gate. That rose grew up left of the gate and has made it onto the shed roof. I'm pretty sure another specimen of it could cover a 10 x 8 x 7 foot shed quite convincingly ...
... and that'd give the chocolate vine something to climb.