We have 5" batts of fiberglass "spinsulation" in our attic, comes right up even to the joists. Our home was built 1972, guessing about R16 +/-. I'd like to add new rolls of R30 on top. However, the existing batts have kraft paper on the top and bottom. Does This mean it has two vapor barriers and I can't lay new insulation right over it or else I might trap moisture in there? Or is this just what insulation looks like and I can just lay new right over it? Any advice would soo greatly appreciated. Thanks.

christy in nj