2 years ago my husband & I built a rancher with a full basement. The contractor installed insulation in the basement ceiling (vapor barrier was installed next to the sub-floor) as we were not sure about "finishing" the basement. We painted the masonry walls and floor - now are going to finish the basement. Is it okay to install more insulation over the existing with the vapor barrier to the outside so we can drywall? (The basement has ductwork however because it is underground the temp remains around 55 degrees without the vents open. We do use a dehumidifier year round to maintain consistency in humidity however there has never been any moisture build-up or water intrusion.