low-e paint or radiant barrier paint
1) Does this low-e paint aka radiant barrier paint really work, or is it all just (excuse the pun) hot air? What about the insulating paints such as Hy-Tech's "Barrier Coat"?
2) I am planning a renovation that includes installing stained beadboard over 2/3 of the wall surface. I am wondering if I painted the BACK of the beadboard panels that are to go on the exterior wall with this barrier paint prior to installation, would it help keep the room warmer? The subfloor is also to be replaced, would it do any good to paint the subfloor's underside before the sheets of plywood are laid (I have yet to finalize the flooring but it is likely to be glued onto the subfloor, which I would guess would do the barrier paint no favors)? The room is over an unheated garage, and while the garage ceiling is insulated and drywalled, there is still a chill (not a draft) coming through the floor.
3) If the paint isn't "all that", what about adhering one of the foil type barrier products onto the back of the beadboard?