Polyshield Reflective bubble insulation is a vapor barrier (solid, non-breathable), 95% heat reflective insulation product manufactured with encapsulated air bubbles between one or two highly reflective surfaces designed to keep out summer heat (heat gain) and hold in heat generated in the winter (heat loss), while reducing moisture condensation and blocking water vapor. The encapsulated air bubbles provide a thermal break to minimize conductive heat from moving through the material.
Polyshield double bubble foil/foil is thicker and stiffer than its single bubble variation. The stiffer material provides an easier install and can help reduce sagging. When comparing with single bubble, it also provides a better thermal break for reducing conductive heat transfer (gain or loss) in buildings. Polyshield double bubble foil/foil material has the same 95% reflectivity as all the other variations. The foil/foil version is usually used inside walls.