Cathedral ceiling insulation
Zone 3 needs R-38.
2×8 truss, 12/12 pitch.
Metal roof, 16 square roof.
Would you prefer:
7 inches open-cell foam, then 2.5 inches on polyiso nailbase on roof, or
BIBS (R-30) touching roof deck and 2 inches polyiso nailbase on top of roof deck, or
Is one option way better than another or way cheaper but as effective?
Or is there a better option?
…than If you had the option of using a vented nailbase instead of nailbase and a fascia vent for some venting under the metal. Would you, at a cost of about $2,500 extra?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part