I realize that 30 is pushing it even with 1" roof
decking. 24" is more common in these parts
(Vermont). I am using 3x6 rafters which are
beefier than normal and putting in some 30"
wide skylights. That's why I wanted to go with
the rafters on 30" to keep the spacing even
because it will be visible from inside. But I
guess I should go with 24-26" rafter spacing
and just frame in around the wide skylights
with extra rafters to the headers as is
usually done. I am not using plywood
anywhere. Thanks,

--
Jeff