Cathedral ceiling insulation for a summer cabin
Need help with weekend summer cabin roof insulation, and best way to avoid moisture problems – zone 4, non vented roof.
Metal roof over plywood over 2×4 rafters, then plan to install exterior siding on interior for finished walls.
I currently have extra 2″ rigid insulation sheets that are R10.
Option 1: Cut and cobble rigid insulation against bottom side of roof sheathing, rigid held in place with spray foam. (1A add radiant barrier paint to interior wall panels which will be exterior siding)
Option 2 : Install rigid foam flush with interior rafters leaving 1.5″ airspace between roof sheathing and insulation. Roof is not vented, there are no soffit or ridge vents. (2A would be paint radiant barrier on interior side of roof sheeting)
Option 3: Install batt fiberglass insulation 3.5″ thick with VB on interior side.
Option 4: Install spray foam – lost of $.
Option 5: ?
Summer cabin primary use with AC.