How Thick Can Foam Be Installed Beneath a Roof How Thick Can Foam Be Installed Beneath a Roof Deck? The Air in My House Is Too Dry. Insulated Sheathing in a Cold Climate. Heating a New House in Nova Scotia. Coping With High Humidity and Mold. GACO Mac or anyone "in the know" -- what has Gaco-Western done with their foam? Can the experts look into their ESR reports?