I am replacing a cedar shingle roof with a composition roof. The
cedar shingles are nailed to battens. I will need to have a plywood
deck in order to put composition shingles down.
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