So we went ahead and bought 2 inch pinkboard from home depot. then installed it over the
icynene because in the winter the 6 inches were not enough on some nights. the pink foam boards are way better insulators in my opinion but i needed to get the gaps filled with foam, hence the foam had to be done first. now we have a cathedral ceiling, looks fantastic, all pink ;-)\
the problem with the smell is still there on a hot day you get a 'wave' here and there. it did help to put the foam boards over it however. we used spray foam cans to seal between the boards and it cost an extra $2k for the entire cathedral ceiling. it was worth it absolutely. it's also a great sound barrier.
problem is the icynene and its smell......
that sweet smell was potent when they installed and then progressively vanished. i think it vanished because it was fall and the temps dropped.
my concern is the stuff may continue to smell forever...hope not!
any ideas welcome. we tried the fans and all that, didn't help at all. when the stuff was installed we had all windows open and fans running for an entire month