Hello there,
I've read on several sites that RBarrier can help keep heat in as well as keeping heat out..

So I have an old cabin the the Santa Cruz mountains. It gets hot in the summer and cold cold in the winter. I'm looking to warm it up. Will do other insulation work but the roof is my main puzzle.

The roof is exposed trusses, redwood plank deck, felt paper and asphalt shingles. I'd like to maintain the exposed wood inside to keep with the cabin feel so I'm trying to figure out how I can at least gain some benefit with minimal insulating above the decking.

I'm trying to figure out what would be the best method of insulating the roof at least minimally..Below is an idea I have but I'm not sure if it will help in the winter months. If anyone can add or provide changes/pointers, I'm all ears.

Trusses, redwood planks remain. Above that I keep the felt (because its black and doesn't show in the cracks of the deck beneath it when looking up at the ceiling from the inside.) Radiant Barrier, Wood strapping 2x2's or 2x4's for taller space, OSB/Ply deck, Felt again and then asphalt shingles.

Would this have any benefit or should I use Radiant barrier with a foam board to help insulate? In the above scenario would the condensation stay on top of the felt which covers the redwood decking.

Recap:
Trusses
redwood plank decking
felt
R barrier
wood strapping
OSB
Felt
Asphalt Shingles

Thanks!

most of the radiant barrier companys recommmend using them on the interior side of the roof, as they need air space to work properly. I do not think 3/4" strapping would be sufficient. if on the interior you would still want to insulate leaving at least 2" between radiant barrier and insulation. If you want to keep the interior look of the roof, 2-3" of ridgid closed cell foam over the roof decking would be your best option. then a new roof over it. I have never seen it done this way in anything other than commercial flat roofs. interior is most likely your best choice. good luck

Tom from www.eebt.org

Homasote makes a nailable panel to which is laminated isocyanurate foam insulation. Install it accoring to the manufacturere's instructions, and then simply install the roofing on it. Insulating value runs about 5.5 or 6 R value per inch of foam, plus a little for the nailing panel.

Thanks! I'll check that out. It might be just what I'm looking for...