I am insulating the ceiling in my garage. The ceiling is 2x8 16 on
center with dead space above. I am using R-30 batts. Now, I know
these will stick up about 2.5" and that's fine for now. But if
someday I put a rough floor up there for storage and compress it,
what's the downside if any? Does compression hurt the R value? It
seems to me I would still be better off then using R-19.

Thanks,
Jim