th attic has some fibergless batting and some blown. we have a split geo thermal heating system part of which is located in the attic. This replaced an oil furnace located in the attic. the attic gets very hot in the summer. I know it needs more insulation and air leaks sealed. my question is, can i put spray foam insulation in the roof area when there is insulation on the floor? will it make a difference? someone mentioned i would need to put a vapor barrier in the floor area. if so under or on top of the insulation?