I have rolled insulation in my attic now and due to age it has started to settle a bit. can i use the reflective rolls on top of existing insulation?

As the Reflectix rep noted, this is not a good or effective location for reflective insulation. The best option is to: (1) Start by sealing all of the air leaks into your attic. Recessed lights are a notorious problem. Create air tight boxes to cover them, e.g. with pieces of drywall taped together with foil HVAC tape. (Do not use foam board, which is flammable.) Seal the edges with Great Stuff foam or DAP 230 sealant. Great Stuff is also good to seal gaps around holes cut for vent pipes and electric power cables. (Do not use Great Stuff next to anything that gets hot, however, e.g. an exhaust duct or chimney -- because it is very flammable.) (2) Install more insulation. The best option would be to add Roxul rock wool batts, which are much denser than fiberglass, and provide R4 per inch. Depending on the climate in your region, a couple of layers may be needed. R38 is recommended for southern climates, and R49 for northern areas. In both cases, the insulation should completely cover your ceiling joists. I hope this is helpful. Mark

We do not recommend using Reflectix on the floor of the attic over existing insulation. In the attic Reflectix is to be stapled at the bottom of the roof rafters.