Use tantalised roofing battens of 50mm. These must be connected for the roof joists using a screwdriver or perhaps a nail gun. Installing roof insulation could be divided into 3 stages—the preparation phase, the set up of an isolating barrier for the vents, and also the installation of the insulation. https://bookmarkmoz.com/story18696402/how-to-insulate-roofs-no-further-a-mystery