Hello all, new member here. I have a 1939 house that has 6" joists with loose rock wool insulation then wood board flooring. Can I roll R30 or R38 batts insulation right over the floor? Will the air gaps in the loose insulation cause problems? I don't really want to remove the flooring in fear of cracking the plaster ceilings (lots of labor too). The house does not have soffit vents if that helps.