How can you insulate a roof that is beams, a layer of plywood and corrugated tin?
We have a roof built of 4" x 6" beam at about a 3/12 pitch, on 36" centers. Those are covered by a layer of 3/4" plywood which is covered with corrugated metal. I would like to add insulation on the under side. Either tack Styrofoam board to the underside of the plywood, then cover with bead board (or very narrow space T111). My other thought is to put wood slats across the face of the beams, place Styrofoam insulation above those, then cover underside with bead board, (paneling, T111, etc.)
The first solution would have no air flow, the second would have an air gap (of 5" or more) but no real flow.
The house is located on the island of St. Croix (USVI), so the lowest temperature is 60+, meaning there will be no real issue of condensation.
The intent is to stop the heat radiating down.
Thank you.
