I have a 1958 ranch home on Cape Cod. The exsisting attic insulation looks like it is comprised of an oil soaked heavy dark paper (on both sides) with a rock wool (like) material in the middle. Total thickness is about 1 to 1 1/2 inches.It was all in excellent condition. Floor joist are 24 inch on center. I may have done the wrong thing ! I recently added 6 1/2 inches of fiberglass batts over the existing dual paper faced old insulation. My question is: do I have to uninstall and completely remove the entire 6 1/2 inches of new fiberglass insulation and then remove the old oil soaked dual sided paper insulation and then re-install the newer fiberglass or can I leave well enough alone ???