Similar to the ground space, the attice is
either sealed off from below and well-vented,
or closely sealed in the conditioned space with
extensive ventilation running up the roof.
Things like maintaining a seal when there's expansion
and contraction have to be covered.
(Like, nails with wider drilled holes and seal washers, etc.)
There are currugated steel roofing materials, but they are
specially made for that, so they don't rot away.