The contractor's I am talking to feel the easiest way would be to put the plywood down over the exisitng battens. 1/2 " cdx over 7/8 " x 1 3/4 in battens. The battens are 5 1/2 center to center.
I assume that they would nail the cdx into the 2 x 6 rafters which are 16 " oc. and not the battens, but I am not sure about that. They would use longer nails to make up the greater depth.
Is there a structural strength issue with this approach? Or would it be better to remove the battens which would be an additional cost.
The net increase depth over existing structure would be handled with drip edging on the rake and eves.
Thanks in advance, Ron