Spray foam (closed cell) directly to roof sheathing? – GreenBuildingAdvisor

Hey guys, so I have a back indoor/outdoor sunroom on the back of the house. It used to be essentially all screened windows when we purchased the home. The framing was rotted out so I tore it all out and added new framing and windows. After the fact my wife wants to eventually make it more living space of course… anyway.

I was going to insulate it myself but due to time and work etc I figure ill get a few companies out here and get pricing. The only company I had out so far was highly recommended from a lot of the builders in the area. However I wasnt really comfortable with what he suggested.

The exterior walls are 2×4. On the exterior I have tyvek and plan on adding 1/2″ to 1″ foam board then siding over that. Interior I planned on doing Rockwool comfortbatt unfaced. I just like it better then faced fiberglass. For the ceiling I am torn… they are 2x8s and im in the northeast in South Jersey.

I was thinking to have the styrofoam vent baffles installed from the soffits to the attic opening to keep airflow moving. Id then most likely add another power roof vent or something in that attic opening on the roof to help remove additional heat. (Cant do gable vent, to many wires and I dont feel like moving them).

The insulator came by and said no, he will do 6″ of spray foam directly to the roof sheathing and r15 faced on all the exterior walls (paper pointing interior) for a vapor barrier. Im not a huge fan of that spray foam idea due to roof rot and no where for moisture to go etc.

I plan on adding a mini split and a return in this room for hvac its about 400 sq ft.

Also I will be raising the floors up 8 inches in here and insulation the floors and adding vapor barrier on the concrete.

Hit me with all of your insulation ideas please.