Screened Porch Ceiling – Insulation Challenge
Climate Zone 6
Screened porch at corner of house: (not a 3 season room)
12′ W x 15′ L x 8′ H
Two sides are exterior walls and will have only screening and railings/pickets
1 story above grade
under footprint of pitched roof with conditioned attic
above a bedroom (porch floor is duradek)
ceiling material is OSB
light fixture in center of ceiling

How shall I insulate the ceiling of this screened porch? Already spent a ton on spray foam. Despite builder assurances, this section was ‘missed’ on original SPF contract (that’s another story).

Plan A: Spray foam floor of attic above porch – $$$ – only labor is spray foam installer, but probably fastest and easiest choice.

Plan B: WRB / membrane (Majvest or Intello) on ceiling of porch and some ?? on attic floor. (I’d rather not have fluffy stuff, as there is none anywhere) Except for a few details done for me, builder has not, and will probably never work with building science materials.

Plan C: ??

Thanks