DETAILS FOR A THICK ROOF. Rigid foam insulation installed above the roof assembly can create an energy-smart roof. With rigid foam above the sheathing and cellulose in the rafter cavities, this roof is about R-63. The three layers of foam help to seal air leaks, but to make this assembly perform well, you need to incorporate some unconventional details.
French drain is a popular term used to describe an outdoor and indoor trench covered in rocks and connected to a series of pipes that carry water away from your house. Please visit the site for more information.