Correct, no attic. It is a low angle roof over cathedral ceiling with
exposed structural members and tongue and groove planking. That room is
cold in winter and hot in summer; a well insulated roof would pay for
itself in just a few years. I guess my questions are mostly academic,
but I also wonder if stripping off the fiber board is really necessary.
I suppose it presents a technical problem if 4 inch insulation is to be
put on above deck. And I would like to be sure that new insulation
will make a significant difference.

Una