Twofold question …..

I have a walk out basement in the planning stage to refinish. The original builder insulated the outside walls with R-19 non-
faced fiberglass insulation and used the CertainTeed MemBrain
permeable vapor barrier (Refer to FH Issue 165-Aug/Sep04 page 38)
I want to reduced my engery cost by keeping the basement cooler in the summer and for sure warmer in the winter. I was advised it was ok to keep the the present insulation with the Certain Teed MemBrain in place and install the R+Heatshield III solid aluminum foil right over the MemBrain. Than run 1×2 furring strips over the foil which will give me a 3/4″ air space after the wallboard is installed. This solid aluminum foil is 1.4 mil thick with a impermeable rating of 0.001. This will give me a good vapor and radiant barrier.

In conjunction with the above; after just reading “No-Mold Finish Basement ” in this months issue of FH (top of page 82). Would it also be worth my while to remove the present insulation in the joist bays and place the 2″ EPS in each bay, then replace the insulation. Or, leave the insulation in place and just put the EPS over the insulation, then fit each bay with the radiant barrier. Or just forget about the EPS all together and install the radiant barrier over the insulation in each bay.

I realize there’s a lot to digest ,,,, but i would value some more field opinons before we start this job. Thank you ahead of time for all your imput on this.