Start up against the wall in mid:
Position your crosshair on the wire in the direction pointed by the beam at the peak of the roof.
This is where the smoke will land:
Around the World Library Smoke
A classic strategy on Inferno. Since there's only one real way into B site (i.e. banana), sometimes you have to improvise... This smoke covers library for the play. It's still important to smoke off porch, but that smoke shouldn't require an explanation.