Closed-cell spray foam insulation: between rafters or joists?
I live in an old (~1900) house in climate zone 5 (southern CT). We are having our attic re-insulated, and have gotten quotes for both rafter (un-vented attic) and joist (vented attic) insulation with closed cell foam. The quote includes 5″ of closed cell foam in both applications. The cost difference is not significant (~$300), and I have read a lot of conflicting advice between the two options. Currently, the attic is vented with fiberglass insulation between the joists. There is no HVAC equipment in the attic, however, we may add central air in the next few years. The contractor recommended insulating in between the rafters and conditioning the space. Any thoughts on the best option based on these conditions?
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