Insulating/ventilating cathedral-ceilinged roof
Greetings all - i'm happy to have found this forum to ask my dumb questions!
I have a circa-1944 house that at some point in its history had the attic finished with cathedral ceilings. Of course I wasn't here at the time, but as far as I can tell they just stuffed some R-13/15ish between the rafters and nailed up some drywall.
Now - it's about time to replace the roof(2-3 layers of comp on top of cedar shingles on top of 1x6 decking). I've been given estimates to tear off the 1x6, redeck it with plywood and install a ridge vent, which got me to thinking about opportunities to improve the insulation and ventilation situation.
Since we'll be tearing it down to the rafters, what would be my best option for adding some space to allow for insulation and ventilation? It seems like we could add some kind of spacers between the rafters and new roof deck?
An additional difficulty is that the house has basically zero eaves... so where would I put the lower vents?
And while we're at it, is it 'better' to rip off the 1x6 and redo it with ply, or does it matter? I've had estimates for both ways.
Since I can't manage to insert it, here is a link to a half-decent picture thanks to Google Street View.
Thanks for your opinions!