Hi all,

As noted, I am in Westchester County, NY (White Plains, NY). I am overdue to insulate my attic, some knee walls, and rim joist. I am looking to do thi as economically as possible with maximum benefit.

My attic currently has mechanicals (an air handler that feeds two zones) and duct work. There is some insulation in the floor but it is pink fiber glass and the house is extremely leaky. I’ve gotten spray foam quotes (mostly everyone wants to do open cell) and at 10k+, I am looking to see if I can get a lot of this done with some hired labor. 

I am considering using some comp of 2″ XPS with canned insulation for air sealing the sides as a first layer. Then looking at renting a spray foam rig. I am wondering if that makes any sense from the hive minds perspective. If this route makes sense, should I be putting a vapor barrier in between the foam board and the plywood?

On the rim joist, what makes the most sense for DIY? I was thinking the foam board with air sealing. My questioin again is do I need a vapor barrier here?

I don’t want to create a drying issue in between the foam and the roofing plywoof (or rim joist). Please clarify this issue for me and any other advice.

Thank you,
David