My 1955 home has a flat roof with 1x8 sheathing. It's time to replace the roof, and I am considering replacing blown-in attic insulation with batts, at the same time.
The attic is only 20" between living space ceiling drywall and roof sheathing. I'm trying to figure out two things:
1) If I should have the insulation replaced from below by creating attic access points in the drywall, or have it replaced from above by removing/replacing the 1x8 sheathing.
2) If there is any reason to replace the 1x8 boards with 4x8 osb/plywood sheets.