Advice on knee wall attic insulation
I am looking for help giving advice to a homeowner where I performed an energy audit yesterday. The home is a 1 ½ story home with knee walls on the south side of the second story. When I accessed the knee wall attic, I discovered that both the roof deck AND the knee walls were insulated with fiberglass batts. The knee wall cavities were filled with unfaced R13 batts and the roof rafters were filled with R19 faced batts, although several of the batts had come unattached and are lying on the floor of the knee wall. The floor joists below the knee wall are filled with unfaced batts (6”).
At first I was puzzled by why this system was installed. I think it was done because there are several heating/cooling ducts running in the area on the floor of the knee wall attic and although the ducts are insulated, perhaps they wanted to make it warmer in the attic to avoid loss of energy through the duct.
What advice should I give the homeowner in my audit report? My first inclination is to remove the batts from the roof deck, increase the knee wall insulation, and blow cellulose on the floor of the knee wall attic to R49. Is there another approach I should advise?
We are in Zone 6 (northern Iowa). I have attached a photo. Thanks in advance for your help!
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