"effi" wrote in message
...
would like to create a cathedral type ceiling in a small area of 24" on
center roof rafters 3.25" thick

within the 3.25 inches thick want: 1" airflow space; and 2.25" insulation

how can the 1" thick airflow space (between 2.25" insulation and underside
of roof decking, plywood) be created?

seems just putting 2.25" thick of insulation without some means to keep
the
1" airflow space open might be a mistake



Seems to me that 2.25" of insulation is a mistake!
Greg