I have a 1950 daylight ranch and the radiant water heating on the ground level is in the slab, but upstairs (Where the main living area is) has radiant water copper pipes in the ceiling and there's no insulation above it. Our heating bills are ridiculous in the winter and I'd like to know how to insulate above the pipes? Do I need a radiant barrier for above the pipes or can I just lay the roll fiberglass insulation over the top of them? I've also heard that I need 3/4" air space and another person told me 6".

This is a rare bird that has this kind of heat in the ceiling so does anyone have any experience with this?

Thanks.